Not clear who actually owns the equity outright. If its the OP, based on what's written and nothing more it sounds like a racket the non-technical founders are running. I personally would identify the laziest path for you to exercise your rights to extinguish the entire venture, ideally with counsel, and then tell the other people what you've decided to do, let them name their price.

If things roll your way, maybe you resurrect the business later buying its assets out of bankruptcy. Either way, think lazy; this looks like a scam for your time; the more you put into it at any price, the worse off you are.