Haven't bought from it but you should understand the return policy (including shipping cost on the return) and the warranty. My mantra has always been if something is going to go wrong (or is wrong) you'll know inside 30 days; if your purchase makes 30 days then the likelihood of it being a dud is probably no different than a new piece. So ensure that you have 30 days to return it just in case it is a dud.
I purchased my PC3 as B-Stock (got a tremendous discount because it was B-stock). It arrived, I plugged it in with headphones and started playing, within 2 minutes it reset itself and within 20 minutes I actually understood the pattern of button presses to make it happen on demand. I put it back in the box, called the distributor, got a return ticket and it was back on the UPS truck the same day it arrived. They sent me another PC3 B-Stock about a week or two later and I haven't had a single issue with that keyboard for 12 years. I gig with it every weekend plus drag it to practice weekly. Solid as a rock. Same with my EV monitor; B-Stock, not a single issue with it, have had it for many years now.