I was in your shoes. I made 2 mistakes. 1st, I bought a worn 650sx that ended up blowing the motor. I didn't know any better because I didn't know anyone in the sport. I wish I could go back in time, never have bought that 650sx, and put that money towards a clean and reliable SJ. Secondly, after I blew that motor, I got involved in building an X2. I wish I could have just parted out everything and purchased a X2, but I was stubborn and as a result I lost out on a whole lot of riding time. I rode more last month on my Superjet than I did the entire last year on my X2. On the bright side, I have learned a lot about skis but I would trade the time I spent learning about them for some time riding them.
I understand where you are coming from, but take my advice... It's wonderful to dream. You should spend every day persuing your dreams. But don't persue happiness. Happiness is an emotion. The persuit of happiness is a fools endevor. It's only present at the moment. You should put your efforts into being happy, and securing future happiness. In other words, If you are always pursuing your dreams, you are likely not living them. YOu will have each one, at the right time in your life.
That may sound like a bunch of babble, but lets talk reality for a moment...
You're in Highschool. Your income is limited. Your spending is not only limited by your income level but it is also influenced by your parents. Even if you had the income, it's unlikely that you could apply it to what you want. (All of the above based on things you have said, not simply generic assumptions).
Building a ski to save money is a great idea. You have chosen an X2 which is great. You are set on building that X2 and enjoying it, which is great. You hope to one day have a Gen2 X2, which is great. But, think about the implications of the path you are setting for your goals.
Your goal is a Gen2 X2. A Gen2 X2 is a SXR with a fixed steer. You have not ridden one, but hopefully you have riden a SXR. SXRs are awsome, I want one myself. It's not a G1 or anything like it. A Gen 1 is completely different than a 650sx made the same year. Motor position, hull design, etc etc, it's a completely different boat. A Gen2 however is a SXR with a fixed steer and a seat. Literally, the Gen 2 IS a SXR, not buts about it. While it is awesome to think about owning a lightweight X2 with a high performance motor, the likely hood of you obtaining one on a college budget is slim if not none, at least not unless you get an awsome job, a fair amount of debt, a few great gifts, or some combination of the above. And lets not forget, the goal is to have one complete when you finish college. Why not just save the money and buy all the parts at once when your graduate, or shortly after? It's not a Gen 1 X2. You buy all the parts and bolt them together. Look at all the AM hull build threads. $15,000, it better bolt right up.
Trying to obtain such things on a college student budget is foolish. I can say such things because I was there only 2 years ago. Don't buy little pieces of a boat you can't ride until you have all those pieces so you can stare at it every day instead of riding something. I could go on, but I will simply end by saying...
Take my advice. It is good advice. Buy something close to what you want. Enjoy that something, whatever it may be. Don't forget your dream, look forward to it every day. Let it drive you to being better and don't let anything keep you from obtaining it. However, pace yourself. That day will come soon enough. Don't be one of those people who has everything only to look back and see everything you missed.
I had 2 jobs up until last month. I suddenly realized that I spent the last 3 years working to be able to ride jet skis anytime I want, but I almost never rode a jet ski. Pretty silly, eh? Well, now I'm in a better spot, and I quit that second job, bought a SJ and started riding it. However, looking back, I realize that if I had never wasted my time on my X2 project, and put all of the money into it, I was only a few dollars away from buying a low maintence ski and actually riding over the last 3 years.
A Gen 2 X2 IS a SXR. Buy a SXR. Ride the SXR. Be happy with the SXR. Save money, buy conversion hood. Be happy with SXR that is exactly the same as a Gen2 in every way except a seat. Graduate college, make mad bank, buy Gen 2, be happy with sick awsomeness. Most importantly, be happy with all the memories of your time on your college SXR as you tell stories of how you really learned how to do all those sick moves on your Carbon.