What should i look for when buying a digital slr?

As far as who has the best deals.

i want a nikon d3100

Costco: $779.99
Nikon D3100 Digital SLR
18-55mm VR Lens
+ 55-200mm VR Lens
Training Pack Bundle
Two Training DVDs
Case, 4GB SD Card
1080p Full HD Video
Scene Recognition System

Best buy: $749.98
Nikon D3100 14.2MP Digital SLR Camera
Nikon 55-200mm Lens

Seems that costco gives you a case with it. If you buy your DSLR usually it doesn't includes a camera bag or something. And a 4 Gb memory card is useful though what kind of speed is it rated at? What CLASS is it?

With video nowadays more then ever being able to write away data quick is important. A slow card can limit the video modes you can use. And a quick card is always useful because it can offer better burst rates. Aka maxing it out camera wise instead of memory card wise.

really when you buy a DSLR you kinda need to add a camera bag to the list to. And have at least TWO memory cards of course best is quick writing. Having an extra battery will be a godsend to.