I am filing my first ever schedule C for a new home based internet auction and amazon sales business. My question is how do I figure my cost of goods sold for items that I have owned for a long period of time. For example, I have sold 50 vinyl LPs and 30 or more I have owned since the late 60s and 70s. How do I place a COGS on those? I obviously have no receipts for them. Another example, I sold a set of insulation hoses on eBay for a net sale of $300 but I originally paid $13,000 for them when I owned a construction business. I did depreciate them for 3 years before the business closed. Non-depreciated value is around $6,000. How do I come up with a COGS for them? Or should I just treat them as personal items sold apart from the business and not report the $300 at all.