What kind of camera do you want to use on it? There is a huge difference between tripods for little point and shoot cameras, DSLRs with smallish lenses, DSLRs with big lenses, video cameras, etc.
You also have to decide how much you are willing to pay. wbeem's suggestion of a Gitzo or RRS tripod is a good one if you plan to use it a lot and don't mind spending lots of money. For most people, they would be overkill. More money gets you lots of benefits (increased stability, lower weight, more durability, greater ease of use, better manufacturer support). Only you can really determine what the right trade-off is for you, but we can help if you give more information about your intended uses.
As to the notion that a $100 tripod performs as well as a $2,000 tripod, well, that's a comment that can only come from someone with no experience with a $2,000 tripod. I could certainly understand someone claiming that their $400 setup works as well as a $2,000 setup. It will in most cases. Somewhere in the $400/$500 range is the point where diminishing returns set in and the difference are less noticeable.