I wouldn't expect any problems with a mechanical steyr, jury is out on the electronic ones as they are still very new - but they do appear to be pretty good. My LP50 was bought second hand and I've put about 15,000 pellets through it and only every give it a wipe down with an oily rag, and the occasional bore cleaning pellet.

The trigger mechanism is simple and robust, and while it may go 'out' as springs age and so on - adjustment is easy. The regulators have been known to fail (very rarely). 'O' rings should be changed every few years - I wouldn't run away if this had not been done though.

Personally, I would not be concerned about reliability if I was buying one - just be sensible when looking at one for sale - if it is dirty, scruffy or damaged, that may tell you that it has not had an easy life rattling about in someone's bag. Adjust the price accordingly; however most you will see will be near mint condition as people who buy these things tend to look after them.

Don't be put off by carved up grips - you will probably need to reshape the grips slightly to fit your hands optimally; so expect some dremmeling and some filling to have been done. Just ask subtle questions about why and how modifications were made. If the dremmel has been whizzing away with the grips still attached to the gun, there will likely be abrasive dust everywhere inside the pistol that may have caused additional wear.

Hope this helps,

McT