i say save it up so u can fix up cars taht u win
if you don't already have one, go win a RX-7 RZ from the Japanese Championship and fix it up with everything, T5 medium tires, and a stage 3 turbo. It should last you VERY long
Welcome to GTPlanet, Haligon. Although I wouldn't have phrased it quite so strongly, I have to agree with Famine and Solid Lifters.
Look at the specs and see what you think. Look for lighter weight and more horsepower... the winning combination. Pick what looks cool and doesn't weigh 2000 kg, and try it out. That's half of what this game is for, learning and experimenting. I haven't bought a car yet that couldn't earn me back what it cost soon enough.
Go for the gusto and pick something that interests you, and give it a shot.