Stupid question, are you just collecting these because the serial number, is that the only reason for these. I got a whole bunch of brand new ones that I spent, didn't know anything about them could be collectible. Perhaps I should save certain ones? Nice photos all your bills by the way!
I collect only new 100$ - Fancy Serial Numbers by the link and thanks : http://coolserialnumbers.com/FancySerialNumbers.aspx