Thanks for posting this. Looks interesting. Something to play with my eldest daughter I think.

I ended up being the local card exchange at university for MTG which was uber-popular. Selling cards made me a fortune simply by enforcing scarcity on some of them and auctioning by email (I wrote an auction system in procmail and perl designed to maximise profit). Made £1320 profit in a year!

Edit: just found my old card database. Had 1540 cards at one point! Still have a box in the cupboard as well according to my wife.