Vintage? What is this wine? No man, these are the ones you can buy on a store shelf right now. Some are better than others. They qualify in what I call "My Rules" for a video game system. So when I can afford one, I pick them up and add them to the collection.
I'm sure there was a guy back in the 70's who looked at the ZONK Pong system and said, "Fuck dude, that's garbage, Atari is way better." And nowadays you can find an Atari Pong pretty damn easily, and it's a nightmare to locate a ZONK. The less popular something is, the more rare it becomes.
Just look at AdventureVision. Probably the most expensive crap console you could own. A working unit can easily fetch $1,000 today without any games. Have the whole collection in mint condition with a box and everything, and you have a nice piece of cash.
So maybe nobody will line-up to buy a Namco joystick. But the kids of today will be 30 in twenty years and they'll see one of these and they'll say, "I remember those." And suddenly their value will go up. That's the point of collecting. Plus my girlfriend likes to play Pac-Man.