Years ago I had a Jennings J-22. I used it for a tackle box gun for years. I paid about $35 for it in a "Gibson's" store back in the late 70s. The little pistol was surprisingly accurate, and functioned better than you'd expect for a pistol in this class.
Problem is, these little pistols have slides made of cast metal, a zinc alloy I believe. aka, pot metal. Some work, some don't. Some can be quite dangerous. Your friend's pistol might be worth $50 to someone who wants it just to say they have a gun.