For less than $500/month for marketing, your options are limited but it's not impossible. You'll have to do much of the work yourself and invest a significant amount of your own time.
Paid advertising is going to get you the best initial hit of business. If you don't spend a lot of time to learn it well then it's likely to be a waste of money, though. So, be sure you learn a lot before you start setting up ads in an hour. It should take you at least 5-10 hours a week just to manage it in the beginning. If you're doing it in less time then you're missing a lot and going to waste a lot of money.