My mom seems never to have heard of purging or spring cleaning, and up until recently the equivalent of approximately seven (7) closets were stuffed with her clothing, not counting the walk-in in her bedroom. I am trying to remove/sneak out at least the clothing from the 1980s & 1990s, stuff two sizes too small, and the rest of my dad's clothing since he died over 17 years ago. She can't take it all to the one bedroom senior residence where she will be moving hopefully later this year.

After a thorough inventory, itemization and thrift shop cost estimation, I managed to drop off a carload at Goodwill. Then I reviewed IRS Form 8283 which you have to submit for in-kind donations over $500. The thrift shop value total for these hundreds of items came to over $500. But there is a place on the form which asks for "Donor's cost or adjusted basis." A dozen or two items still had tags, but I have no idea what she paid for the rest. Any ideas on how to complete this?