During my current PCB design using Altera FPGA, I happened to come across knowledge that Altera EPCS devices are to be used for FPGA configuration. After further research, I realized the same job can also be done by normal generic Flash-NOR of any make. In fact Cypress has an Application Note to this effect to (let's say) promote their own Flash chips for this purpose.
My question (and this baffles me truly) is that what's so special about the Altera chips that they charge $37 for the same as Cypress and others' chips which cost only 60c? Also does anyone know special cases or applications in which Altera EPCS chips are preferred?