For a couple hundred bucks more, you could get a brand new set of Rotas (or another brand) in a variety of styles with four brand new tires. Honestly, if you don't know for sure that the wheels and tires are 100% perfect in terms of functionality, I would pass. Because you have an all-wheel-drive vehicle, the tread on the tires must all be within 1-2/32" of each other in order to avoid any ill-effects on your differentials. When buying used tires, there's really no telling how the tires have worn due to aggressive driving, over/under inflation, damage from debris, etc. One or more of the wheels could have a slight bend too and that's nearly impossible to figure out just by looking at it. It would be a shame to spend that much money on a set of wheels/tires just to find out you have an odd vibration somewhere and you can't figure out where it's coming from. If the price is too good to be true, it usually is. Save up and get something you'll really like.
07 WRX (Albins 5MT + Blouch 20G)
Jorge Carrillo Tuned (365 whp/340 wtq)