I have a difficult time believing you're going to generate much cost savings drying your own herbs unless you're also the one growing them. A 1.5 oz jar of dried basil costs a buck at the dollar store, and it takes more than half a pound of fresh basil (about 10 cups!) to produce an equivalent amount if you're drying your own. That's easily $5 or more worth of basil at typical farmer's market prices. There are culinary advantages to using fresh herbs in some situations, but I'm skeptical of the claim of cost savings.

I'll second the recommendation of buying in ethnic markets if you have access to them, especially if you can buddy up with some friends to do a "group buy". (Speaking from personal experience, it takes an undogly amount of time to use up a quarter-pound of coriander unless you use it all the time.)