what to run

Nothing like jumping in to the deep end of the pool to learn to swim. LOLOLOL
Top Sportsman IS under 7.99 to run , but you'd best be a lot closer to the 6's if you want to compete.
I don't want to sound like I am not for you being all you can be , but I think a ton of homework would be in order before you find your " home ".
Heads up classes..........well , a good used motor can be had for your budget.
Not within your budget.........your entire budget.
Can it be done cheaper ?
Certainly.
But cheaper seldom equals competitive.