Umm, you pay taxes on a private sale too. Taxes on $3000 are $202, plus 5 bucks for title transfer. The only thing you don't pay on a private sale are dealer "doc fees", but there are plenty of intangibles that a dealer sale provides and a private one does not such as inspections, fixing broken parts so it's in resellable condition, and most importantly, accountability in case there are hidden issues and things aren't as advertised. That being said, you are not a dealer. Unless you find a mark, you aren't getting $3000 for that bike.