I scored a 2016 Scott Genius 710 on eBay for about $2600. It was new in box; I had to assemble it myself, and if I have problems with it I’m sure I’m just hosed. But still… Amazing bike for the price. It wasn’t my first choice, but who cares? I have a sick bike that’s super fun to ride now
Plan on spending about $400 additional for anything you buy used, in my opinion.