$500 sounds nearly right but only if it has a title and is registerable.
Rugged machines, otherwise. I had a '74 F7, which was renamed the KE175 the next year. Nice enough machine. Pulled me around town at ~45mph and did fine on ordinary trails. It had a fantastic ignition, I remember that. I've never seen such a fat blue spark from just easily kicking it over. And it never ONCE fouled a plug on me.
Good luck whichever way you go.