Expensive modules may be applicable for 1 to 5 up on product.
as I said Then I suggest you look into www.phytec.com and buy a P89C668 development board. I have done prototypes with this board and had no problems.
My affinity for the 668 comes from the fact that it has 64k Flash and 8k RAM internal to the chip. In my "world" I need the RAM and less than ~4k forces me to add external RAM. Adding external RAM "kills" port pins and then you need external circuitry for I/O. A 668 design using internal Flash and RAM gives you 32 fully useable port pins.

Erik