One of the best things about setting up a home workspace for bicycle maintenance is that most of the bicycle tools you'll need don't cost very much. And, if you're on a budget, its easy to start slow and buy a few things at a time.
Organize your buys by category. For instance, one month buy all the tools you'll need to take care of your wheels. Next month, you can buy what you need to take care of the gears. By doing it this way, you are able to take control of your bicycle one section at a time.