Well, I really did mean that high-school/college-age demographic. I was perhaps anomalous, but between saving up for college in high school, and then paying for college and rent while I attended college*, I would have been hard-pressed to afford even the $100 mark. The moment I started an actual job I had more income than I knew what to do with, after those years of minimal spending.
But you're right, in that it isn't a very expensive hobby when it comes right down to it. You can make everything you need, with the exception of the big-ticket items that aren't necessarily crucial anyway. You can form your own hats, sew your own clothes (even cut stockings out of wool if so inclined), carve and finish your own truncheon, make your own belts and boxes - which is where I am. Unfortunately, in my case, I also have a burning desire for evermore 'details' that continue to bankrupt my hobby funds.
*And I didn't even own a car, with all of it associated costs.