Usually when I resell an instrument I make a profit or, if I'm selling to a friend, break even. There have been a few exceptions. Tomorrow there is a good chance I'm selling my tenor sax and I don't know if it will be one of the exceptions because I can't find out how much I paid for it. I bought it in 2000 My credit card bills only go back to 2003, discover's records only go back to 2008, paypal only goes back to 2012 and ebay only back to 2013. I did find an email with the tracking number for it, but no email with what I paid. Oh well, I will likely never know, but I know know a whole lot more about my online records.