I have heard, but had some bad experience with used raquets, besides, many used racquets may be compromised even if they don't seem damaged.
And the KPS88 is already out of production, there are many threads where ppl involved with Wilson told that Wilson can no longer provide them with the KPS88 for it is discontinued, and the price reduction on TW confirms that.
Ok. I can understand that, but in my experience, a regularly used frame is quite durable and using some good judgment, asking the right questions, and having good pictures of an item from a reputable seller will still net you a good deal on a used frame.
....and as of this post, you can still get the kPS88 in any available grip size from TW.
I was excited about the kPS88.....until I hit with it. It's just too powerful and too stiff for my liking. I would use it if I had to, but I've instead gravitated to my current favorite. A 26 year old Wilson midsize model, the Wilson Graphite Force. I've obviously had to buy the frames used and have been extremely happy.
I even like it more than the PS85. I was happy with the PS85 until I came across the Graphite Force. I was pleased to find a nice solid midsize that swings easy and has good punch on the volley with good control all-around. In retrospect, I realized I was tweaking my PS85s to have more control and stability. Higher string tensions, adding lead at 3 and 9, etc. When I came across the Graphite Force ($10 at the local used sporting goods store) and took it out for a hit, after the first ball I knew it was my "new" frame.
Back to the kPS88, even at the now discounted prices of the kPS88 ($150 each if you buy 2 or more) I'd still be able to get almost 8 of my current favorite on the used market. Availability is an issue especially for grip size, but sometimes patience pays off.