That Spas has a few things going for it.
The folding stock is usually more desirable to collector's than the polymer fixed stock, and the attached carry hook only adds to the value. The magazine extension adds more value, just make sure the spring still has good tension. The barrel is the most desirable one piece design, as opposed to the two piece add on. See, when they first started importing the Spas into the USA, they originally came with a 14" barrel. The early Spas had barrel extensions soldered onto the factory threading to extend the barrel up to the legal limit. Your Spas has a one piece barrel... much more desirable.
However, there's one big thing that will hurt you, and that's the lever safety. This is a major hazard, and was recalled back in the day by Frachi. The safety was changed to a traditional push-button safety similar to those found on other firearms. Don't rely on this safety... it's very dangerous. If you can find a trigger group with the push button safety, buy it. It will cost ~$150, but will add much more to the value of the gun.
Finally, the only thing I can't comment on is the recoil buffer. In the back of the aluminum frame above the trigger group is a polymer recoil buffer with a metal plate attached to it. These become old and frail after exended usage, and are prone to breaking. If this breaks, you'll know it because the metal disc will be clanging around in the frame, or might just fall out. These are a pain in the butt to replace, but it can be done. The guy who runs
www.spas12.com makes replacement buffers.
All in all, I'd say you could expect to get $1200 if you sell this Spas.... maybe $1400 if you find someone who has been looking for one for a while.
Here is mine. Fixed stock, two-piece barrel, short magazine, push button safety. I paid $450 out the door for mine back in March, and I've been offered $1000 on more than one occasion. But for me, it's just too cool to get rid of.
http://picasaweb.google.com/vex.donuts/Firearms
On that same page you can see a target I shot with my Spas from 50 yards with Federal Premium slugs. If you have any questions, feel free to let me know. I've done alot of research on these things.
This use to be my home protection gun, but I use a colt 45 and a mossberg 500 for that now. The mossberg is easier for me to move around than the SPAS-12. The SPAS is a bit to bulky and unweilding to me, but for sheer terror factor, and the fact that if I pointed this at an intruder, he would stop whatever he was doing and I would not have to pull the trigger
