I have an SP1, had it a long time. If you'll check around you'll find they are worth a lot more then most other ARs including the new Colts.
Just for info, I was at a gun show a couple years ago and was looking for a pencil barrel to put on my SP1, with a 1:7 twist.
I like the light weight of the SP1, about as closest you can get to the M16A1 I used in Vietnam, but I wanted to shoot heavy bullets.
Anyway, back to the gun show, I thought I was gonna get mobbed. A couple venders and customers started giving me holy hell for thinking of screwing up my SP1. Ruining a classic collector piece.
The begged me to just buy another rifle and make one.
Just do a search on SP1 prices............BEFORE the recient price jump they were going for $1800-2200.
BUT your's in "unfired" NIB, If I was going to sell it, I wouldn't talk to anyone for less then $3000.
But again, mine has been shot, (not abused, still in excellent shape) but I wouldn't sell it for $3000.
Nah, I'll just let my kids or grandkids fight over it.
I did decide not to rebarrel it. Not like I don't have other ARs I can shoot that can shoot heavy bullets.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071