There are plenty of grass roots series all around the UK which are easy to enter and fun. Hillclimbing for instance is very cheap and great fun you can use you road going car with very few things need for saftey eg. Fire extinguser. If you go to www.msauk.org you can find loads of information on different types of motorsport. When you enter you are covered on competition insurance. As for cost, how much does it cost the average person for their games consol, games, controlers, TV, surround sound and much more. Bet it adds up to quite a lot?