Not OP, but these kind of boards are ballpark between $100-$200.
Here’s a similar board with the same FPGA: https://www.crowdsupply.com/radiona/ulx3s.
Another similar board (perhaps even more similar than the ULX3S) is the IceSugarPro - it's sub-$100 for the module and breakout board.
[I enjoy reading your blog by the way - just last week I picked up a Pano Logic G1 on EBay!]