Yup. Unfortunately eBay is the reason a lot of better games are so damn expensive, even if they're rather common games. Like Super Mario World for 35 bucks? Please!
I was in a flea market booth a couple of weeks back and this young couple walks in and asked about a SNES with Super Mario World. The kid working the booth sets them up with a yellowed system, a working copy of the game (cart only), and pair of controllers that look like they'd seen better days. The cost? $125. The young couple didn't even bat an eye, paid the kid cash and we're on their way. I was kind of stunned as they could have gotten a used Wii with a Nintendo Selects Super Mario All-Stars and a used Classic controller to plug into the WiiMote for half that price (and get more games out of the package). Kids these days.
Back on topic, Truxton is one of those games I've seen/held many times over but never got around to picking up. I could have it for $20 all day/every day and then suddenly I turn around and it's fetching $75-90 practically overnight.