I don't think hover boards will ever be mainstream (or at least for like 100 years). For this reason, I would try to extract as much money as I could as quickly as possible. I believe when the hype fades this domain will hold less value. Then again, what do I know? lol
If I paid 1-3k I would be aiming for 7.5k+. If I couldn't get more than that... I'd grab whatever profit I could and run.