just offer him $20.0 Its an OLD OLD kart, but who cares about old when it needs so much work? Has aluminum rims, which are notorious for chipping and breaking. If it was a complete running kart with a padded seat, then $200 would be fair.
right now it needs a
$100 engine
$15 brakes
at least tubes to go in the split rims which are $15x4 so $60
$10 chain
$60 seat
$20 rear bearings X2 so $40
$3 front bearings x 4 so $12
and a ton of time to do it all, not to mention paint.... Its not a question of IF there's rim or frame damage/pitting/rust but how bad and where is it?
Is the axle straight?
what about spindle brackets?
what about spindles?
So you tell that guy you will give him $20, and be prepared to go up to $30 or $40 max, otherwise you will be putting a ton of money into this thing. Enough said. Maybe you can even offer to pick it up from him for free so he wont have to throw it away.
I just had to edit this because itsid posted. My opinion is how USEFUL is this going to be, not as a showpiece/collectors item.