For those of us that have restores, I have a spreadsheet with current PC's on my USB as well. I usually buy in lots, and then fix them up, so ebay receipts aren't usually actual value - ponies in the condition some arrive in are worth way less than once they're cleaned up and have a new lease on life, so once a month I update any prices with the PC archive, and add in any new ponies, taking into account any flaws, accessories, etc...