Check out bikesdirect.com. They have different models at different price ranges. They have some nice middle of the road bikes for under $500. At least that will give you something to look at and compare others to. Maybe you'll find something similar at home. If you want used. I wouldn't hesitate at all with buying something off of ebay. In fact I've bought two bikes there myself. If you know what to look for you can get a lot of bike for under $500 on ebay.
I got this Surly 1x1 for $370. I've added a few things, but I got the basic bike for that price.
