There's a fair number of retired guys racing in SRF. Once you get over the initial hump of getting a car and a towing setup
*, it's a pretty cheap series to run
* - On towing - the car as-loaded is going to be in the ballpark of 1500 lbs. Some forums report guys squeezing them (just barely) into 7x14 trailers. Even if you went with an 8.5x18 to make it easy to load and have room for tires and tools, you're talking a grand total of about 5000lbs for the whole loaded rolling trailer, which makes even a 1/2-ton truck a reasonable towing option if you stick a Class IV hitch on it...