Have you compared the actual running costs of a 150/152 vs. a modern Rotax-powered microlight/VLA, or vs. a diesel-powered aircraft such as the DA-40 TDI or Robin Ecoflyer?
Particularly in Europe, fuel prices are a very large percentage of your operating costs so if you can get significant savings on those, by using a frugal engine, or one that can run on mogas or diesel/Jet-A, you may actually be able to offset the higher depreciation of the inevitably newer aircraft.
My club charges the exact same amount per hour for a VFR C152 as a VFR Robin Ecoflyer. Obviously the 152 is at least 20 years old (after all, production stopped in 1985 or so) and the Robins are brand new from the factory. Guess which ones are fully booked with lessons and which are not?
(Edited to say that the club tries to keep cross-subsidies between aircraft types to the minimum, and tries to keep prices in general as low as possible. So the rental price is actually quite a good reflection of the operating costs, plus a fixed amount per hour to pay for non-aircraft-specific club operations.)
Last edited by BackPacker; 18th Feb 2008 at 20:45.