Perhaps if you have a systematic tripod, you could use a leveling base instead of the center column. You could also just use a shorter center column instead of the one that came with your tripod.
Another, perhaps better, way to save weight is to buy one of the carbon fiber offerings. I like the ones from Gitzo and Really Right Stuff, but these will blow past your budget. I am sure that some of the less expensive ones would work for you, but haven't had personal experience, so I cannot make a suggestion as to which.