how much is it worth

[houndman]

i have a atc 200s my cousin found a guy that has a moter that he will sell says it ran when they pulled it out (you know how that goes sometimes) im thinking of it more so for parts for mine any idea how much is the right price to give for the motor? i havent looked at it yet i will today just hopeing to get some kind of idea how much it would be worth before i do any and all input is greatly apprieciated

[yamaha225]

i bought a rollin frame an 2 motors 4 $100 i would give no more then 50 4 it cause u have never seen it run an u cant see it run