It’s not small runs. The second edition/printing (1.5) got about 20k KS backers, which is really high. As other have said, the margins here are very high and they are making money at 50% costs, so over 50% margins is likely (they sell direct, so there’s no distributor or exhibitor in the picture).
As for expansions. The current 12 expansions sell for a combined $800, so that would be $1200 for a full set of game+expansions at store price, which is certainly insane. I would have never got into this had it not been for the KS offering stuff at half price. And it was still a budgetary stretch at the time.
I recommend people play the game, but I can’t recommend people buying it.