There is no single definitively correct way to do it, but there are multiple ways to approach the problem. Almost all of these methods can be played around with on a good inflation calculator like the one at Measuring Worth. Which one you choose depends on what kind of insight you want to produce. The key to remember is: there is no such thing as a durable unit of real value, and the quest for such is a fool's errand.

The easiest shortcut method in the case of coins made from precious metals is to simply take their metal content in terms of mass and ask how much that much metal is worth today. In the case of 5,500 pesos. The peso was (numismatists, feel free to chime in here, I'm approximating!) about 27g of approximately 90% pure silver, so that's about 24g of silver. Around this time 20 years ago, silver was worth about $5 USD per troy oz., which is about $0.16 per gram. 5,500 of them would cost about $885. or about 750 Euros. If the question you care about is "how much precious metal would you have to give up to buy that ship then, and how much is that worth now" then that's your answer. (We are discounting that the purchasing power of a coin was not always exactly equal to the value of its metallic content, which leads us down a whole other rabbit hole. But it shouldn't diverge *too* far.) Pretty cheap for a ship! But then, we haven't accounted for changes in the availability of silver either, and silver has been getting cheaper (at least in terms of gold) since the early 19th century.

The other method is to focus on the object itself: "how much would it cost to make the ship today?" Or, relatedly but not exactly the same: "how much would this ship be worth, if you just found one lying around?" This is not usually the question people are interested in, but it certainly offers a useful perspective on changing value in history.

So, another way to do the calculation would be to ask how much of something would that silver have bought us, to try and get around the problem of inflation - the price of everything else increasing in terms of silver. We could use grain, to figure out how much food you'd have to have given up to buy the ship, then ask how much money it would cost today to buy that much food. Or we could use hours of unskilled human labour, how many hours would you have to work to earn enough to buy such a ship? Or if we wanted to be engineers rather than economists, we could calculate how many calories would need to be expended to build such a ship, and what those calories would cost in food or in fuel. That gives us some different ways to compare, ones that are no longer tied to the value of sliver, which has changed over time.

But again we run into difficulties. All of these things have changed in value as well. Technology for building ships allows us to build bigger, better, faster ships, meaning the modern value of such a ship would be very low, at least as a method of transport. Growing grain is much easier today than then. And the productivity of an hour of labour in 2000 is obviously not the same thing as in 1819. So even if we reduce it to labour hours, or to caloric consumption, or raw materials, or foregone grain, or whatever else, we fail to find a clear single unit of comparison.

What then if we use a bundle of goods, rather than a single good? That way, you have something equivalent that is not sensitive to the price of any single good. Then you must construct a basket of goods, and compare the price of that basket of goods then to today. But people do not consume the same things in 2000 as in 1819, and the further our actual basket of consumption deviates from the one we're using to measure inflation, the less useful it is as an actual reflection of wealth. The price of candles was very important in 1819, and almost totally irrelevant in 2000, whereas the price of electricity in 1819 was not even a meaningful concept, but was a crucial question in 2000...

So, perhaps, then we might want to update our basket over time, to try and preserve its plausibility as a measure of inflation. We can, say, have a broad category called "illumination" and substitute in the relevant technology. We can then avoid critical failures due to new goods and obsolescence, but we are now embracing an apples-to-oranges method of measurement. Most historical price comparisons somehow rest on this sort of updated consumption basket comparison, because the question of interest is usually "how have standards of living changed over time?" So, the question would then be "how many of the 1819 basket can you buy for 5,500 pesos, and how much would it cost to buy that many year 2000 equivalents"?

There are another few methods, that I personally find to be dark sorcery. But, so long as we're trying to be thorough, it's worth thinking about them. One is to ask "if I took 5,500 back then, and invested it in some kind of risk-free asset (British consuls are usually used), how much would I have today"? This can create very large numbers through the magic of compound interest. There is a certain sense to this, but it doesn't really reflect anything important about purchasing power, which is usually what we want to know about. In the real world, there are no immortal investors whose perspective we need to consider, and real-world wealth faces issues like destruction, taxation, inheritance taxation, and so on, it doesn't just compound year on year to infinity.

The other dark sorcery method is to ask "what share of the national or global economy was 5,500 pesos in 1819, and what would that same share of the economy be worth today?" This gives, to my mind, a highly distorted picture, as it implicitly assumes that we do not care at all about the explosive growth of the world economy. This sort of reasoning leads to bizarre results like the Dutch East India company being worth twenty times as much as Microsoft, or Marcus Licinius Crassus being the richest person who ever lived, or whatever else. They are correct from their perspective, so long as we remember that we are only talking about shares of the economy, but this diverges very, very far indeed from the more intuitive "how much would it have bought me" calculations.

All this to say, there are many ways to do this calculation that would yield radically different answers. None of them are correct in any fundamental sense, but all of them frame the question in a different way. What we really want is the holy grail: a durable unit of value, consistent across time and space, into which we can reduce all other quantities. But this is to mistake value for a fundamental property of things, rather than what it is: an expression of how one particularly clever bunch of East African primates manage the problem of resource distribution. Not subjective in the sense of entirely arbitrary, but an ever-changing bit of social technology and not an objective, measurable feature of the universe.