You might be new around here, but there's this thing called Free Software where (although that isn't why the word "Free" is there) the marginal charge for more copies is indeed less than five cents and often effectively zero.
Of course modifying the software isn't cheap, unless you're going to learn how and do it on your own time, but that's not a marginal cost
Not so new, but if we price things soley on manufacturing costs Apple products should be a factor 2-3 cheaper while Windows and Office should cost, what, a Dollar max? Not to even think about luxury and brand name stuff. Manufacturing cost is only part of the price calculation, software just sits at one extreme end of the spectrum.
Disclaimer: My private daily driver runs Ubuntu and LibreOffice.
Of course modifying the software isn't cheap, unless you're going to learn how and do it on your own time, but that's not a marginal cost