I buy items at garage sales and Craigslist to sell on Ebay, but I dont get receipts. How do I deduct the cost of what i purchase without proof?

[pk]

there is nothing that prevents you from claiming the expenses except  if you get audited -- I would claim but would have notes, check stubs, bank statements to show what I spent on each item and what I sold it for.  As long you have an honest/best effort, there is no crime in claimimg some expense -- the tax system operates on honesty of the taxpayer