I started racing FV's when I was 20 years old because the SCCA changed the age from 21 to 18 the year I turned 20 (1973).
The one expensive concession was my dad buying the Zink kit for me at a cost of $1500. I built the car from the kit, I built the engine from VW bug parts scrounged for several hundred dollars in the junk yards. I then bought a cheap used engine from my FV friend. I converted an old horse trailer to an open trailer at a cost of about 50 bucks and pulled it with a cast off car of my dads with 200k miles. I slept in a tent at almost every race. I got better at setting up the car and at building engines. The only pro engine build I ever had was prior to the 1978 runoffs. I was hoping that would bring me home first
I bought and scrounged and was given used tires form the front runners until I got closer to the front myself. In 1978 I ran 8 races including the runoffs. I bought 2 new sets of tires. I started while I was in school and spent every dime I earned in the summers on the car. I was fortunate that my parents footed the school bill. My dad, he was investing in a different kind of education, one that has paid dividends over the years.
You can't do all that now. No VW's in the junkyards to speak of, but there are plenty of cars available with pro built motors ready to go. I did it again a few years ago after about a 35 year absence. I bought a used car at 4k and rebuilt it for little money and lots of time. I did OK and had a lot of fun. Life got in my way or I'd still be racing. Maybe next year.
The point - you can do this in FV without spending a fortune - IF you want to do it. You don't need a motor home but it is nice. You don't need a closed trailer but it is nice. You can sleep in a motel at 125 a night or buy a big tent and cot for 125, and use it more than one night. You do not need a 50K truck to pull the FV. Your street car will work. You will have a lot of fun.