I wouldn't worry about it, since I'm planning on using some of that excess donations I received from Game Theory and Phil21, who between them almost contributed the whole sorting fee themselves ($271,) so just thank them!
If you really feel bad, the cost to ship domestic, not including the envelopes etc is about $2, international ~$3.75. You all should have my paypal on file by now right? Lol.
Anyone else missing keys let me know, I've got a list going, and it looks like Litster got Soulpyre's ~ key. XD