I suppose the good side of the secondhand target pistol market is that you will very often find the pistols are very well looked after due to the nature of being indoor target pistols. My Steyr is 5 years old now but still immaculate. My Walther 400 is also in excellent condition too which I bought secondhand and I had a Steyr LP50 before both which was still mint and secondhand. Perhaps I've just been lucky, but I haven't seen any pistols that look like they have been abused in my time shooting 10m at clubs and competitions.
The Walther 500 is lovely but so expensive, as are most pistols now. I recently inquired at the East Midlands Range (shop) about Walther servicing and they can do them no problem.