As mikej says Altera & Xilinx makes good and affordable FPGA. There is no reason to compete with them.
But an ASIC for a stable version of the AGA core + cpu can be interesting to improve performances. For that you can use Hardcopy chip from Altera between fpga and asic. It's an FPGA without the memory layer and with fixed routes. So with your FPGA design you can have a fastest chip without redesigning it from scratch (just deal with some timing issues).
