The main difference between Z142 and Z242 is the engine - the former features a Czech Walter M337, the latter - a Lycoming IO-360. While M337 is a slightly bigger engine and may consume a bit more, it is designed for 78 octane fuel and may be operated on mogas, which brings the operating costs down. I am based in the Czech Republic and, judging by the rates charged by local flying schools and clubs, a Z142 is marginally more expensive to operate than a Cessna 172 even on avgas, and definitely cheaper than similar basic military trainers like Bulldog.
A maintenance facility at my base aerodrome, LKBU, overhauls Z142s and sells them with full TBO (as far as I remember, it's 2000 hours on both airframe and engine) at fairly good prices (with bespoke paint and avionics kit). I can ask them for details if anyone is curious - feel free to PM me.
Morane, there is a modification to eliminate the 600 hours limit. Furthermore, the wing spar is pressurised with nitrogen and has a pressure gauge in the cockpit, so it's easy to diagnose for cracks.
Last edited by Ultranomad; 15th Sep 2012 at 15:37.