I've picked up a few consoles second-hand from the likes of eBay, Facebook Marketplace, and Shpock.. No issues so far!
PlayStation (original) - I still had my original PSone (slim), but wanted to dabble with the
PSIO which isn't compatible with the newer model. The condition wasn't too shabby given it's age!
PS2 Slim - Months before I'd sold my original PS2 having re-purchased the "remasters" for the majority of games. Trouble is, for many of them you can't beat the original experience on the original hardware. Looks to be nearly new.
PS3 Super Slim - I was just transitioning from Xbox to PlayStation at the time, and having owned a PS3 previously which sat collecting dust, wasn't sure how well I'd adapt. It made sense to spend less on a used console.. One of the rubber feet are missing underneath, but that's about it..
PSP - I'd originally planned on buying a few of these, modding them and selling them.. The screen has a few marks, but I'm not sure if they were there before or after I'd purchased it.
PS Vita - Probably my worst purchase of the bunch.. It's an original OLED, but there's a fair bit of superficial damage to the console surround itself. The screen is fine, and everything plays ok though.