If I cared badly enough about the mission and it wasn't a for-profit enterprise, I'd take the pay cut. The non-monetary part of my compensation (the feel-good factor and the actual good done in the world that I can't get in a for-profit enterprise) would more than make up for it, at least for a couple of years.
Market rates don't matter all that much if the person setting them has a significant influence on what they are. It's like a child determining their allowance based on which one of their friends was able to grab the most money from their mom's purse.