Afterthought - The main advantage of sprint racing is you can run the car ‘as is’, there is a road going class, which allows you to do this. You can also qualify for a ‘B’ license, which goes along with the car, as run. Any car which is ‘prep’d’ as a sprint car needs an ‘A’ license, which you can’t get till you’ve qualified as a ‘B’ driver.
You will need a ‘Shut off switch’ (ignition ‘kill’ switch,) which must be located according to general rules and be visible to any marshal who may need to use it after a crash, or a fire. Clothing - overalls must be flameproof, and shoes, socks etc are also preferred, as is underwear. A crash helmet, according to the rule book. IIRC - you need to compete in at least eight events to gain enough points to cover the season, many attend more than this. No event is ‘next door’! I follow on sprint driver - a former Club member, and every event must cost him between £400 - to £450 with entry fee and accomodation. Nothing comes cheap any more.
Racing is a different kettle of fish - Apart from specified clothing, you need to pass an ‘ARDS’ test, the car needs a total strip down, passenger seat, carpets, trim and any non essential bits. It also needs a full roll cage, which add s to the bill. Also a full race harness is required. You normally cannot drive to an event, you need at least a trailer, and a hefty beast to tow it. Or, if you are loaded, a converted truck or other large vehicle that you can drive to the next event with the car onboard, or towed beínd it. Some even tow a caravan, accomodation isn’t cheap, and you need to stay overnight for either sprints or racing. Entry fees are also expensive, the reason many race drivers need sponsorship. A good driver - and car, may win races, this keeps the sponsor happy, being a tail end charlie ends in withdrawal of sponsor, so that’s the spur that keeps you foot hard down. Then there’s the spares list, which can be endless, depending on your season.
Never heard a driver say how much a season has cost, but my guess is at least £10K, probably more. You need to be committed totally to racing to allow you to shrug off the cost - that’s apart from ‘preping’ the car - are you? In F1 you can even ‘buy a seat’ if daddy is a millionaire and you are a good driver - the team needs the money. Otherwise it’s a hard life, starting at 5 year olds.