I have the chance to buy a Colt SP1 AR15 without a forward assist on the upper and is in about 98% condition.  He got it back in the Late 70's or early 80's but cant really remember when exactly he bought it because he has two of them and can remember witch one he bought when.  He has only put about 300 or so rounds though the gun total.     If Anyone who could give me a idea of  what a SP1 of this type is going for you be helping me out alot.  basicly I need to know what a fair price is on this gun to figure out if he is given me a good deal.  

$1200 is about what I have seen around here for a clean SP1. That'd be about tops I would spend, unless it was NIB with all accessories still packaged.

I just did a quick search of the EE--$800 ones sell fast, $1200 ones sit unsold. That should give you a good idea.