G'day umrum,

I agree with o'sulldj that if you have the discipline you should restrict your betting to Group 1, set weight and black type races. You can usually refine the chances to a small number of runners and utilising dutch book betting you should be able to extract a fairly reasonable POT each year.
These type of races are usually spread fairly evenly throughout the year all over the nation so there should be enough action to interest the serious punter.
The only downside is that in some set weight races the odds can be compressed somewhat and you may have to apply a betting strategy to turn the odds in your favour.
I am sure that if any punter had the DISCIPLINE to bet only when the odds in such races gave him/her an advantage, they could make racing pay.
The important factor here is DISCIPLINE and to bet only when the odds are in your favour(dutch book betting for example). I know how difficult this can be so it is up to the individual as to how they approach their betting.

Cheers.