So, this was surprisingly hard to answer! But, as a weaver interested in both historical techniques and history, period, I was intrigued and wanted to know for myself. I already had a pretty good background in the warp weighted loom used by contemporary Scandinavians and Anglo Saxons, and knew about the vertical two frame loom used by the Romans, and that the horizontal treadle loom was in use in Europe by the 12-13th century: How hard could it be to fill in the blanks? Well, hard enough that I can't give you a complete answer, and it may be too vague or far away time wise that I messaged the mods to get clarification on the "incomplete or partial answer" rule. So, here is my best effort, fingers crossed that it helps you out!

So, to best answer your question, we need to know: Are you a man or a woman? Are you living in the country, or in a city or town? If you're a man living in a city around 1300, there's a lot less evidence, so I'll address the other hypothetical personae first, then get into the uncertain territory.

First off, a little history: During the 13th century, there were three types of looms in use: The vertical two beam loom, possibly brought over by the Romans, the warp weighted loom, used in Britain since the Bronze Age, and the horizontal treadle loom.

The warp weighted loom is mainly identified in the archeological record by the weights themselves, and even those are often misidentified and argued over. Essentially, the warp is attached to the cloth beam at the top, and is held taut by weights at the bottom. What kind of weight depends more on location than time period, but clay and rocks are the most frequently found material. There's also a wide variety of weights found around Europe, from 100g to 4 kilos. In Anglo-Saxon Britain, loom weights were mainly annular or donut shaped, and weighed between 150-500g. The last set found in Britain were dated to roughly 1150 C.E., which is around the first time a treadle loom is mentioned in Europe. (Rashi of Troyes described the loom used by professional "weavers who weave by foot" ie treadles, and "the loom used by women", with a "rod that goes up and down". Some interpret this as either manually changing the shed or beating the last pick in.)

I have no experience with a two beam vertical loom, so I won't talk too much about them here. Variations of them have existed in different cultures, but the main differences between this and the warp weighted loom is there are two tensioning beams, and you weave from the bottom up instead of top down. They both used string heddles, to raise alternating warp threads. There are suggestions that despite its well documented use in the Roman empire, the two beam vertical loom did not achieve widespread use in Britain until the 10-11th centuries. (I can share my speculations on this, based on my own experiments with the warp weighted loom, if anyone is curious.)

These two looms would have been your choices, were you a rural woman weaving for your family, the same as it had been for centuries. Both are fairly simple to construct, and require no specialized parts, so replacing it was as easy as buying or finding timber. And warp weights were just rocks or clay, so no major loss.

There is also a little evidence of individual specialist weavers scattered throughout the countryside. For example, in their account rolls of 1266, the nuns of Lacock recorded payments for both weaving and fulling. Speaking of fulling, one of the earliest suits of fullingmills is recorded in Wiltshire County. This required even cloth woven for home use to be processed at the lord's fulling mill, just like grinding grain. While there were earlier fulling mills, one just outside Marlborough was listed on the king's rolls and in 1215, was worth £4 a year. Despite the eventual proliferation of fulling mills in Wilshire (taking advantage of easy access to water power), in the late 13th and early 14th centuries, Wiltshire exported more wool than finished cloth. Obviously, the best quality wool is going to sell first, so local weavers were mostly producing and exporting lower quality cloth.

So what about the Weavers Guilds, you ask? The mass production of cloth for sale, as opposed to what the wife made for her family? Well, that's harder to track. The earliest evidence we have for the guilds of weavers comes from around 1130. In one Pipe Roll (or Exchequer account) from the reign of Henry I, there's a record of a payment to the King from Robert son of Leofstan on behalf of the guild of weavers of London, another from the sheriff of Lincolnshire on behalf of the guild of weavers of Lincolnshire, and by the weavers of Oxford on behalf of their own guild. The weavers of York and London were granted charters by Henry II, London's stating "Know that I have conceded to the Weavers of London to hold their gild in London with all the liberties and customs which they had in the time of King Henry my grandfather". These would have included the right to elect their own bailiffs, supervise the work, collect taxes and punish defaulters. If you're interested and not prone to headaches, take a look at the Ancient Book of the Weaver's Company. I couldn't get anything from it, but perhaps someone else skilled in reading old documents can.

Being a weaver meant being hemmed in by a lot of rules. Besides the length and width of their work being strictly regulated (this was even included in the Magna Carta!), the laws get even worse if you're not a freeman. Depending on your location, you couldn't go outside of town to sell your cloth, nor could you sell it to a merchant or a stranger. Some attempted to get around this by the merchant giving the weaver yarn, then the cloth was returned to the merchant, so in Marlborough, you could only weave with permission from the "good men of the town." In Oxford, you could weave with your own yarn, but you still had to have permission from the town burgesses. Marlborough gets even worse, directing that the craftsmen shall not own any property worth more than a penny, except what is needed for his occupation and 5 ells of cloth for his year's clothes. Was this law actually enforced? No idea, but the mere fact that its on the books is pretty telling. Going back to the craftsmen VS freemen I mentioned above, craftsmen could not accuse or even give evidence against a freeman. In Beverly and Winchester, if a craftsman managed to become so rich he wanted to become a freeman, he had to forswear his craft, get rid of all his tools and then, after he had satisfied the town magistrates, he could enter "La franchise". Marlborough was even stricter, requiring three years without weaving before you could apply. In 1316, the merchant guilds tried to monopolize the sale of cloth, with "all weavers shall give only 12 pence yearly to... The Gild Merchant for every loom, and shall henceforth be free in all things concerning the gild of merchants, except stallage." Stallage was the payment for the right of having a stall on the marketplace, so weavers were getting it coming and going!

But thats about it for evidence from the 12th and 13th centuries. Central and local records are few and far between. No customs accounts, and few court rolls, and even fewer wills and letters to tell us anything about the Men themselves. The closest I can come to telling you how much a loom might have cost is from the will of a weaver in 1621 in Oxford, who left goods, including his own loom, totalling £31. Would your weaver have been able to pass down his horizontal treadle loom to the next generation? Absolutely! Besides the fact that there are at least 3 more wills I've seen looms mentioned in (although this was the only one with a monetary value attached), the technology has changed very little even up until now. In fact, I'd bet that you could transplant a medieval weaver into any modern home weaver's workshop and they'd have very little trouble picking it right up.

What might also be of interest is knowing what your weaver has coming. In 1337, a statute was passed, protecting all foreign clothworkers, promises them such franchises as may suffice them, "a man may make the cloths as long and short as a man will"!!!!!, and banning the importation of foreign cloth. And at the time, there was already a lot of tension between The Weavers Company and burrelers, who wove cheaper and lighter cloth. By 1370, the Weavers Company had already slipped down to 9th place amongst the guilds. And of course, the Black Death wasn't far off...

Also affecting your weaver was the overall change from worsted cloth to woolen broadcloth. To give a highly simplified explanation, worsted spinning creates a tight, compressed yarn which translates to the finished cloth. Woolen spun yarns, on the other hand, are airy and almost fluffy, with uncontained ends. Here's a website explaining the difference, with pictures. All that air gets compressed out when fulled, and those loose fibre strands get tangled and locked together, resulting in a dense, heavy fabric. By 1500, the standard broadcloth was woven to 2.75 yards wide, 24-26 yards long and weighed up to 84 pounds. While warp weighted looms could be 2-3 yards wide (based on loomweights left in place when a house burned down, most produced only 10 yards in length. I can't verify this myself, but John Oldman estimates in The Economic Impact of Clothmaking on Rural Society 1300-1500 that the weight of the standard broadcloth went from 38lbs at the beginning of the 14th century to 64lbs mid 16th century. The increased difficulty in duplicating these products for home use may have combined with the rising demand for spinners to gradually end home weaving.