A 150/152 be a struggle and impractical weight wise unless you are particularly skinny (if you instruct for any length of time you will get skinny for free anyway
).
You will just be restricted to larger aircraft. 172's/Warriors etc.
I've only started instructing very recently and really enjoy it, also I've already noticed the improvement in my own flying. However, once I have 500 instructional hours or so I realise that the main gain from then on will be Total Time, not particularly experience.
Why don't you get a share in a cheap aircraft and fly the arse off it. It should get cheaper the more you fly it. I know some of the PFA types you can fly around for about 20pph.
I've had to go back to my "fairly well paid job" in IT for the winter period so as to make next summer a lot less uncomfortable financially speaking
