It's a strange hobby. You might get an old moped for $250, and replace everything to make it safe and functional, rebuild the engine to deal with 40 year old seals, bearings, and gaskets, then spend a few hundred kitting the thing. So now you have a turnkey bike that you have spent around $900 on.
But when you come on THIS SITE for advice regarding selling it, the bike is only worth half or 75% of what you have into it, because they know all of the work involved and put no value on the new parts you installed or your time. Especially your time.
Then they PM you and lowball.
Oh, you have something special, it's just that nobody wants to pay you for it.
Put it up on an online auction with a reserve price that makes you happy or ride it a few years to justify the price's depreciation, but don't come here looking for an idea of what a bike is worth. We are cheap bastards.