@scalz We develop with GNU tools and that is what we provide. Lots of IoT operating systems can run on our board, to name a few Zephyr, RIOTOS, ARM mbed, etc. The programming depends on which of these OS you use i.e. ARM mbed can be programmed using their online IDE and as well as GCC toolchain.
Cost per unit of EP Board isn't cheap as the board is meant for production use and it has features many COTS boards do not have - refer to project site for details. Design can be modified to reduce the cost. We are not selling the board at this point as we are yet to arrange funding for the project, fabrication costs good amount of money, once we have that the next step is to stock a few and sell. Thanks.