Cheap[ish] Digital Slr Camera! Good ones?

I'm 15 & i'm really starting to get into photography, after winning a few competitions with my little sony cybershot. But i'm looking into i bit of a better camera. But, i also am not the richest person in the world, & don't have $600 dollars to spare on a camera. My mom has a nice digital slr, sony cbershot, D… Something, & my friend has a niice Nikon. But is there anything out there you know of that's somewhat cheap, & good quality?
I would appreciate your help!

Well, I looked into this and I found 3 slr cameras that might interest you and I ordered them from highest price to lowest:

http://www.amazon.com/...B00005OCWN

http://www.amazon.com/...B0007WK8KI

http://www.amazon.com/...B00005K2R0

All 3 have interchangeable lenses and they are reasonably priced for you.

Cheapish? Well if $500 is cheapish go for it.

I recommend what I own and know… The Rebel XS (1000D) I've had mine for over a year and it's just excellent giving me exactly the results I want.

I would suggest Nikon D3000 10.2MP Digital SLR Camera
* 10.2megapixel CCD sensor
* 11-point autofocus system,
* Fast response, Guide mode,
* 3-inch TFT,
* 3 fps continuous shooting allows you to capture fast-moving action at 3 frames per second
http://www.amazon.com/...002JCSV5I/
http://rover.ebay.com/...m270.l1313