How to make the most out of 200$?

I am self-employed in the education business. At the moment, I'm not that well paid, I make about 25$ an hour. So I have to work a lot to have a descent lifestyle. Sometimes I think about taking simply 200$ and trying to make the most out of it, by reselling things, investing them in online advertising for some kind of simple webpage, etc. What would you do to maximize those 200$?