The problem is only the size of the board - the bigger they are, the more expensive... you don't want to build something the size of a NuBus board if you can avoid it. In particular with more layers and/or more sophisticated processing.
hehe, perfect timing:
IIsiA7 Mini. My first design with onboard FPGA. However, it's 6 layers and double-sided, so even more expensive per area (the savings come from not needing the daughterboard!).
The IIsiA7 Mini is not that expensive. The true cost isn't in building the hardware, it's in supporting it - I just don't have the time... Doing a couple dozens at a time, the cost would likely be below 100€ per unit (depending on the FPGA, and how badly the supply chains are f*ck*d by AI madness and the war in the middle east...).
The only board I've given up on because of cost is the QuadraFPGA; it's the most useful (as Quadra have the horsepower to actually exploit the larger screen and better audio), but the connectors are too costly. Not per unit, but the only source left is Mouser (or similar) with a MOQ of 200 at ~13€... 2600€ for a large box of connectors is a bit much for me. At one point there was some NOS (new old stock) left, but all the wells appear to have run dry by now :-(
