MAX10 FPGA versus Cyclone V

Professionally speaking, assuming that because I was able to buy a few Cyclone development boards (more capable than I need for most of my designs) automatically means I can afford to purchase 10,000 more Cyclone V chips just for production, would be extremely unprofessional. I'm sure you know it is very unlikely that any of my projects use exactly every feature of my development board.

I'm not saying you don't know this but: Always look at the design, once completed, and choose the less-capable chip that can handle that design with a more reasonable price. It sounds very much like this is what they were asking for.