You have come to the wrong place to ask what something is worth. It is against the rules.
The seller must have told you how much he wants for it. If you can afford it and want it, it doesn't really matter what someone else thinks it is worth. If it makes you happy, then buy it
Are you good at fixing things and fabricating parts? if so, then buying a project minibike can be very rewarding.
Welcome to the Madness.
Keep us posted on what you do to it.
You can get parts for them without too much trouble. There is a Wanted section in the forum along with a parts for sale section. Search them and post what you need in Wanted. We can answer other questions for you no problem, just not it is worth.
Danford1