Not true, during kickstarter, they claimed that the 500k USD they asked for is supposed to be 10% of the budget and the rest would be paid by the investor (i.e. at least 4,5M), and that was with expected release date two years ago, which means the expenses are in the end a lot higher. They also got over 4M usd just in crowdfunding (though you need to deduct all the expense like tax, rewards etc), than there was 1M usd investition before the kickstarter to make the prototype. And then you have Deepsilver, who are most likely investing in marketing (which is also relevant when you mention 81M usd for Witcher, since HALF of that was actually only for marketing).
Budget of KCD is easily over 10M USD just for the development, IMO over 15M considering the delays, but that is only a guess. They have team of 100 they need to pay, if you do basic math using average wage in Prague, they need 2,7M per year only for wages of their empolyees, and I think they pay a lot more than average wage considering they need skilled programmers and other high qualified jobs…