Now, yes, I know butter makes everything better. I agree. It's fantastic and makes things that taste good taste GREAT. Real butter is, however, a little pricey. If you're in a financial bind, but still want your cookie fix, try subbing either stick margarine or shortening for the butter. The texture is great and it still tastes fantastic. It is imperative to use a stick margarine that is not reduced fat. They contain too much water to make a great cookie. I usually opt for the shortening route. It's really easy to work with and I usually have some on hand for pie crusts and biscuits. Make sure you don't over-cream shortening or it'll toughen up.
Try it out...it'll save a bundle...of cash, not calories!