$300 is too high, but $50 is too low. 3D print sellers aren't doing injection molded parts at scale, nor offshoring the labor. For GP's linked case file; between the filament, the compatible linked switch and fan hardware not purchased by the thousands, and someone paying themself at least minimum wage to print all 46 individual parts and then to partially assemble and package it up nicely (and not counting printer hardware depreciation or electricity), $50 for it is not a viable product to sell or to run as a business. That's the price I would budget for making it myself with the 3D printer I already own and not counting my time as a cost, not something I would waste my time with selling.