For $299 I want as close to an original-part-by-part reproduction, not an FPGA cheat.
For an FPGA cheat, just publish everything open-source and sell a completed product for those that don't want to DIY.
I'm willing to compromise a bit on the FPGA front for individual chips that are unobtainum, have no modern substitute, and not cost-effective to recreate in small-ish quantities. However, the substitute chip should be pin-compatible and of course timing-and-everything-else compatible with the original. In other words, if I had a bin of original parts and a bin of the FPGA substitutes, I should be able to use either one in a rebuild without noticing the difference. The motherboard, connections, and feasible-to-reproduce parts should be faithful reproductions of the original.
I'm hope this product is successful, but it's just not for me.