That picture you linked... I don't know, but I'll guess that goofy pistol goes for like a zillion dollars.
I really, really wanted to show a picture or link to the goofball I'm thinking of, but my search-fu is WEAK! There was an issue of Guns & Ammo back when I was in my formative years in handgunning and they had an article on goofballs. Palm pistols, pen guns, the Dardick, the Gyro-jet, et all.
They also had this "thing", it looked like a tool you might use on a farm. It had a grip like a handgun, two barrels and hammers like a muzzle loading black powder front-stuffer. But also, it had two huge prongs coming out of it, looked like spears or miniature harpoons. They didn't shoot off of the handgun, they were just built in to it. Like you'd stab your prey, then shoot it if it gave you any trouble.
I'd have to actually go to the cave and dig through old magazines to find it. I'm too lazy to do that. But with that limited info, does anyone have the search-fu to find it? I have no name for it, and only my weak description.
If you want goofy, that fit the bill.