I would definantly start out in semi-pro. My husband and I both started racing this year and he jumped right into pro and wow was that an eye-opener. After the first race, he dropped down to semi-pro, and although there are still some awesome racers, he can at least compete a little closer with them.
Here are some things we learned this year....
-You can always find race-ready up sleds this time of year at pretty good prices, as many of the racers are selling them to make room for next years model. This is great if you are just starting out because you dont have to go out and buy all of the extra stuff you need on the sled to race. We just picked up an Assault last week, completely set up to race with only 170 miles on it from a well known pro for $7400
-If you are going to run semi-pro, don't worry about getting a turbo sled or a sled with nitrous, as you can't race those in semi-pro.
-Personally I would focus on making the suspension on your sled as sweet as possible. I think you get the most return from a sled by having your suspension set up perfectly...ie re-valving shocks, buying after-market shocks and making other adjustments. You can always work on performance later when funds are available
-Be prepared for the expense....This sport is super expensive, especially if you live far away from the races. Most of the races this year were in Eastern Idaho/ Western Wyoming. For us, it was a minimum of a three day trip. Unless you have the money to spend, try to find ways to cut costs....stay in your trailer one night, bring food from home, carpool, etc.
-Have some savings set aside in case of trouble, you blow a shock, need belts, a-arms
-Try to find sponsors to help deflect the cost. You would be suprised at the businesses that will give you money or other help in exchange for their company logo on your trailer and sled.
-Traction is key! When you get your sled, you must have screws for almost all of the races. We started out with some from studboy, they did pretty good for most of the races. For some of the races like Afton you need more aggressive screws. I recommend cold cutters. They are a little more expensive but are twice as aggressive. If you are going to run improved stock or mod you can also use titanium paddles, which are about $200 for 10, so they are very expensive as well, but they work
-Start practicing as soon as you can. Find somewhere that you can pound in a course and hammer it. Even if it starts getting trenchy and rocks start showing keep riding it because that is what you will be riding. If you practice on nasty hills, then hopefully when you race it will be a piece of cake!
My husband and I both love this sport. We have met some of the most generous, fun people while at the races. Most everybody is open to helping out another racer. Just be prepared that this sport isn't for everyone, and it is not as easy as it looks on the videos! If you have any more questions, just send me a pm and i will try to help you as much as possible