I've noticed the same!
I remember learning at Archerfield and being in the circuit with eight or so other C152 / PA38 etc... All gone now, though.
I hope it can be made to work - I am trying to put together a flying school capability (Part 141... OMG) using a Whitney Boomerang (a solid little training aircraft that I reckon is a good design, but never succeeded because a) it is an Australian design and b) got smashed in the market by the LSAs, Grobs and other designs that are manufactured cheaper overseas) which I can use for the right price and a C152 Aerobat that I have had completely rebuilt from scratch - putting both aircraft out at under $200 per hour wet (without instructor). Probably be somewhere about the $250 per hour for dual training once up and running. Both aircraft are in very good condition - which is a fundamental tenet of the business as no-one wants to hire an aircraft that looks old and tatty...
I'm probably mad, but I have a particular business model in mind that I think / hope can work.
Apart from the detractors who will say to give up and not take the risk, anyone with experience in this sort of thing got some good advice that might help??