The best prices for DSLR's are online from the large stores in new york (B&H Photo, Adorama, etc.) As stated above, the retail stores (Walmart, Best Buy, Sears, etc) do not have a lot of room to reduce the price. The price reductions come from wholesalers and manufacture discounts.
I cannot post links since I am new, but B&H Photo (search in Yahoo or Google) has a Canon Digital Rebel Xt for $510. You can get it for less ($429) without the lens.Typically you can find lenses for relatively cheap on Ebay.
Perhaps the most important part of the camera is the lens, particularly for sports and low light pictures. Canon (or Nikon) typically make good consumer quality lenses, but they can get pretty pricey. You may want to look at Sigma, Tamron or Tokina for lenses. They make them to fit pretty much every brand of DSLR camera and most of the time are much cheaper than the manufacturer's lenses.
Now, for consumer cameras (Point and Shoot).... Keep in mind that mega pixels are not all that important, unless you plan to make large poster prints (11x14, 20x30 and larger). You can make excellent 8x10 prints from a 3 mega pixel camera (I am a professional photographer and I have done that with the early DSLR cameras). The manufacturers make it sound like you need more mega pixels than you really need, increasing the price of the camera. Mega Pixels DO NOT make a better image... they only make enlargements better (less grainy).
Sorry for the long post. I hope this helps.