I had the exact same thoughts you did when I bought an Ultra LX-1 2 years ago. I was new to 1/8th scale buggy racing and wanted to get in cheap. I already had a radio and servos, and the $280 price tag got me in. Everyone at my local track was telling me to get a race buggy from the get go, but I didn't listen. I wish I had listened to them. After a couple of race weekends, about 4 diff ring gears (as Working Man said) and a couple of test drives with a friend's Losi 8ight, I had to get a better buggy.
Long story short, 1/8th scale equipment is very durable and can take the abuse of a new racer. If you plan on racing, get a better buggy to start with. Losi, AE, Hot Bodies, Mugen, etc.