It is difficult to quantify but, in my experience, there are really four grades of tripod
1: really crap - it looks like a tripod from a distance
2: way above crap - fairly stable, won't fall apart but won't tolerate much use, any travel is rough and not especially rigid. These are usually with integral head. (Velbon is in this 'I'll use it until I realize I need something better" category) - ~65 or 70
3: decent - well-made, sturdy, pretty flexible and will handle virtually anything you need - up to a point. Bogen-Manfrotto is the leader here - separate legs, head, flexible, multi-grade and lots of options. - anywhere from $125 - $280 gets you a decent legs/head. - where I am now
4: terrific - more expensive than I need.