i found someone selling a used but in very good condition hks hypermax
whats a good price to pay?

 

low-ball the chit out of him and give him 600-800 bucks granted they are in excellent shape and not blown.

if they were to be blown and leaking they are worth 300 bucks tops.

 

they are almost perfect. do you know about the ride height of these? are they old school, ride height= higher spring rate? or are they independently adjustable?

 

spring rate is never a function of ride height

spring rate is a function of ... the spring

what i think you mean is that overall length is not separately adjustable from the spring perch- meaning that you have to droop your springs to go lower

and that does seem to be the case with these

 

you have to know how to low ball people. its a skill

if you really want to slam the car and dont want the spring to droop/sag you can get a set of helper springs.