If you start out in the 7sx class (basically completely stock) you will get the jist of racing and start to become familiar with it. As long as you do your own fab work cost can be very low for the vehicle. To race in an event its between 500-1000+ but it depends on the lenght and time for the race. Starting in the 7sx class will give you a good foundation to start off of and from there you can upgrade your truck as your drving skills increase and move up to 7s then 7 open.
Now unlike the big guys, there is no need to race EVERY race. you can pick and choose your races for the year and jsut have fun with it. Dont expect to go out there to beat everyone your first race, if you do i owe ya a few beers lol. the way i look at this type of racing is, im not out there to beat the competition, im out there to beat the desert. As long as you finish its a win in my book. you may not understand that now untill you get into racing and realize what its all about but trust me, its hard work but well worth it