Hey I am 17 as well, and ride a 125. I have tried other bikes, and one bike I rode, a cr250r, while it was fun, it made you lazy. I am talking about the 2 stroke 250. A 125 really requires you to be on your toes. Keep the 125, I doubt that you would have the skill to use a 250's potential. Not trying to be mean, but I am in the exact same boat as you. I pay for all my own bikes, maintenance, entry fees, you name it. Keep the 125, rebuild the entire thing over the winter and enjoy it. Also, adjusting your sag is probably the most important thing you could do.