How old is it and is it scoped? Take a good look down the barrel and make sure it's all nice and clean. Is it 209 primer fired if not I'd pass on it. If scoped and 209 and all is nice $150 is probably fair. Try to get all the goodies with it.
I agree with huntingman on this one, the knight lk 93 used #11 percussion caps compared to todays inline's using 209 ignition.
I would spend my money more wisely and go with a newer inline. Good Luck