If you ask me, they should first try doing it themselves. Be it research or design, the founders need to do it on their own. Only then, they begin to understand what UX is and are in a better position to make a hiring decision.
I'm a strong believer in providing fishing rods rather than fish. I am and will continue to mentor my team (and others) in running *their* research studies. I will get involved when complicated research projects are at hand.