If you would like to have an office away from the distraction of the busy house. Investor Dean has a plan to create your own private office in a corner of your garage. Get you work done in quiet while still being at home. I like this idea. Instead of being interrupted all the time you could go out to the office. The article is from a couple of years ago so it would probably be over 500 but maybe not by much.
How to build a DIY office in your garage for under 500 dollars