That is a question that has many conditions, but as an average I would guess between $300 and $350 around here. That looks to be from 1975. Prices vary from region to region and with condition of gun.
These make enjoyable project guns. I took one of mine and cut it back to 4 5/8" and made a great little gun out of it. I just wish I had been smarter and bought up a big supply of ammo when it was super cheap.