Any good C-D series for a budget racer?

Hey guys,

I don’t know if anyone can help me with this, so I’ll try to explain: Last season someone pointed it out to me, and I was able to race the minimum 8 races in the Sim-Lab Production Series and the Ferrari Series by just buying the 488 and Watkins Glen.

Is there a C or D-class series this season that one could participate in and complete at least the minimum number of races necessary with a maximum of 2-3 item investment?