I would not have anything involved with the company after he takes control, especially financially. You don't want $70k dependent on HIS ability to keep your customers happy. He may take care of your customers poorly and they all quit and you're out 70k.
You're asking 230k his offer was 200k dependent on 70k from customers sticking around on HIS work.
I'd tell him 180k take it or leave it and go from there. He's not the only person in the world that may be interested...