the thing is, you can't just get good at something like this and have the time and money to participate in higher level racing, mainly because of how things are run.
You can't race at high level without backing from a decent team of people who usually require payment. Let's not even go into the costs of equipment, UNLESS you are part of a professional team, in which case, you have to be one of those people who can do the crazy feet shuffle, in the dark running at 90+mph pointing at trees and cliffs.
on the other hand, if you work to get a job that makes you enough money to afford to go racing every weekend, unless you are in the top 1% who gets paid lots for not doing a lot, you are going to have very little time, even on weekends to have fun. When you do have time, you would probably want to spend it with family and friends instead.
this is going to be a bit pessimistic but I'm not sure if you can have a good paying job and be able to race regularly at the same time, unless your work is race related.
here's the pages from silverstone that I've been reading maybe once a month for a rough guide....
http://www.silverstone.co.uk/html/ma_become03.php