I know I'm an odd duck, but I actually don't plug stuff in that I buy, until I've got a use for it or an interested party.
For one thing, I'm always in a hurry and usually exhausted when I unload a truckload. Then I'm usually in a bad mood because I spent money I either didn't have or shouldn't have spent. And the last thing I need is the added depression / frustration of discovering that one or more games I was promised were complete and working are actually not.
So I just pile them into the warehouse and save the adventure of examining and testing them for later. It does add some fun to digging out a game - not knowing anything about what you'll find.
I would bet I'm unsusual in this. I've learned that I have lots of psychological quirks/oddities, but I choose to embrace them rather than try to change them.
Of course, all that said, it's hard to imagine listing something on eBay without plugging it in to see what it does. I think I've done it a few times with really old games with frayed cords that obviously were not going to work. But if it's got a good cord, yeah, I think anyone would plug it in.