E-beam litho is...uh...not cheap. The system in the shared fab I use (WNF) costs around $450/hr with various discounts applied. Also, you're not going to get much done in just an hour. Now, maskless laser lithography is reasonably cheap...

However, you can get reasonable quality masks for $150ish, and if you don't care about wafer yield, you can fit all of the layers on one mask. It's 1970s tech - 1:1 contact exposure, but you can hit a few microns.