In my estimation, buying it back isn't good enough, at this stage -- you already have considerable expense just retrieving it. And, would add at least that much more, returning it ---- sooooooo, if he is willing to buy it back, he should be willing to refund that much expense, and you keep the bike.

That would help to make you whole.

If you want to keep it, go ahead - but at least give him negative feedback for misrepresentation......