How to handle items I sold in a Facebook group

[Babydmom07]

I think I know the answer to this, but wanted to check to make sure I'm doing it the right way. Last year in the fall and before Christmas I sold some of my kids clothes and toys in a local Facebook sales group that my kids weren't really using. I am confident that the sale price of all items was less than the value paid. Some of the items were gifts from relatives, but I sold everything at such a low price that I'm sure it wouldn't have been more than what they paid for the item. 

I'm putting these sales in the same category as garage sale proceeds, and from what I understand, the money I received would not be counted as income because they were sold for less than the original price. But do I have to have receipts to prove this? I would think that it would be logistically impossible to do so. Am I correct in not considering these sales as income?

[IsabellaG]

If you sold used clothing and toys for less than you paid for it, you would have realized a nondeductible personal loss. You would not report the sales, and you wouldn't claim a loss. It wouldn't be reasonable to expect you to produce purchase receipts for these items, but if you sold a significant amount of these items, you should retain a list of what you sold, what you sold it for, and an estimate of the original purchase prices/ages of the items in the off chance that these transactions were ever questioned. As an aside, your cost basis of items received by gift (from your relatives) is actually what the item cost the giver.

[Mighty Squirrel]

On a similar thread - I sold kitchen cabinets from our home we purchased a couple years ago. I have no idea what they originally cost. How do I determine cost basis?