I'm asking purely out of general interest. I love the 13th century arms and armour. I wanted to know how much it would cost for a knight to be fully equipped with a sword, lance, horse and any other arms and armour I may not be aware of. Also how much it would be relative to the time. Nerd question, I do apologise.
Here's an answer from a slightly later time period. It might be of interest, although metallurgy techniques and trade changed a bit between the periods.
Edit: also, it's from /u/waritter