To be clear, cartridges were extremely expensive by modern standards, and took forever to get made. That was literally the original point and timing of E3 - Toys R Us, Kmart, Kaybee, and whomever else existed back then would see the game at E3 in the summer, order 50k/75/30k each, and that would determine the publisher's initial cartridge manufacturing order, which hopefully would be made in time for Christmas.
God forbid if you wanted larger than average roms - those NeoGeo games were $200 to $300 in 1990 dollars (~$500 to $700 in today's dollars), and even the large SNES-era RPGs creeped into the $70 range (like ~$150 now).
Obviously the much cheaper disc printing costs and then downloads helped manufacturing costs, keeping game costs below inflation rises, and then DLC 'subsidized' the initial prices, but even the 360 era saw costs bump up to $60. Costs have continued to rise, for one single reason - art. All those unique art assets add up quickly, and those have been what have driven game costs. The industry saw some success in offshoring that work to places like Singapore and China in the 360 era, but even those costs per manhour have caught up, and game prices have risen accordingly.