I bought a mad max model car at auction. Had researched before and seen they were selling for £500 - £700 on ebay depending on condition. I got it for £20 and then found out it was missing a headlight, but still got £227 for it. So get that priced and get it sold.Bought a porcelain bowl last year - for £80. It's got a gold mark on the bottom, that looks like a vicennes mark circa mid 18th century - they're usually blue, but gold would suggest it was commissioned as part of a set for royalty - possibly Louis xv.
I figured I'd do some research and find it's value to be mega... I've not looked into it and it's sat in a draw in my bedroom