This varies greatly depending on how often you want to race, and how competitive you want to be. A typical social racer, who competes in a 6-round state series will likely spend around $7,000 per year in maintenance costs, which includes tyre purchases, engine rebuilds, crash fixes, race petrol, entry fees, license fees, and accommodation costs. A serious racer who wishes to race at the front of the field, attends 8 races or more each year with perhaps the interstate national challenge race, and who attends a handful of practice days throughout the year, could spend around $15,000 to $20,000 for a season of racing.
You may also consider leasing a drive with a Formula Vee team. Leasing costs vary, dependent on a number of factors. Generally drive and arrive packages start at $3,500 per round.