I know everyone buys lots and so it can add up quickly, but seriously just don't buy a coffee or something one day and forget about all the exchange rate and who to preorder with crap!
https://www.youtube.com/watch?v=Wm4_Fd3whbU

Half of the threads on here are turning into "where are you getting it from/what are you paying/oh that's good/oh that's bad/i'm getting it from here/i'm getting it from there!"