Michael Dunn have done a research on FPGA boards available for less than $100. We all know that hobby market is always looking for low price hardware to do amazing projects. We already have almost free microcontroller boards including 8-bit and 32-bit ARM. FPGA always were was behind barrier. Not things seems to changing.
Today you can get quit several FPGA boards for your projects that are under $100 limit. You can find boards from Altera, Cypress, Lattice, Microsemi, Xilink and even more that aren’t listed. The lowest price you can find is like $4 for PSoC 4 FPGA board (at least more or less). In that price range you can get up to 22 kLE (logic elements). This is more than enough to run soft processor, build calculus intense projects like signal generators, scopes, signal processing modules and other projects where microcontrollers wouldn’t have enough juice. It takes some learning to get used to them, but there is quite enough tutorials to get started.