Getting an office is a great move. I worked from home for quite a while until I ran out of room. Now we work from a 2000sq ft office and things couldn't be better.
It all depends on what you are doing, if you only need a small room, you can usually find them in an out of the way part of town for $150+ a month. Money well spent and also a tax write-off. Start by looking in the paper and then by asking people. Just make sure to find a good person to rent from.