Request for help to select an appropriate FPGA IC?

Can't you use a microcontroller for that application instead of an FPGA or CPLD? You would require next to no external components, and it is more in your price range. I don't see the benefit of programmable logic for this application, except if the cryptographic requirements ask for a hardware acceleration, but in that case a Max II will probably not be enough and the FPGA solution will cost more than what you want anyway.