Even the palette-swaps generally cost anywhere from a quarter to half a million dollars to do properly, unless it really is cookie-cutter. I don't know the exact figures, but the company I worked for spent a sum in that neighborhood on an e-commerce site, and laughed at me when I told them I'd build them a new site in house for a modest pay raise. Software is really expensive, programmers have this blind spot around it I think because it's psychologically easier to undervalue software than it is to face the reality of economic exploitation.
It seems you have experience in this area and I don't want to belittle it, I won't contest your claim that you've done it for less, but I want to be clear that the expertise that allows you to do that is worth a lot of money, even if you didn't get paid for it. How much? Take $1 million and subtract what the firm actually paid to bring the new product to market, and there you go.
If it's your company, then you get to enjoy the competitive advantage that the cost savings affords you. If not, the people owning the company are arbitraging your expertise and they're getting the competitive advantage.
But it's not just your expertise. Your team has to be a cut above in order to build software products for less than the general market rate. Again, they are either getting compensated for it or they're not, in which case they form part of the competitive advantage of the firm. The entire Silicon Valley startup industry is organized around creating and exploiting this advantage, which is really why it seems to you that a million bucks is an outlandishly huge number.