Bit of a late reply, but :-
The Spec Racer Ford (SRF), which is a free car, has a beginner friendly schedule where you only need to buy three tracks to compete in a "full" season of 8 races. They plan so that they either repeat a track (on a different config) or have 5 free tracks. So a rookie should be able to do a season for around $30. They also limit how many tracks change each season, to reduce the ongoing spend.
And the SRF, on the NTMv5 is a hoot

Like the skippy, it is a car which will teach you good habits, which help down the line.