A BizDev role (with or without MBA) is generally dead weight and a liability to the P&L for most startups under 24-30months old. All the capital, every damn cent, is generally needed for Engineering , Product , Vendors at that point.
The founders also need to be doing a lot of the BizDev , as it's largely customer development at that point... and potential customers want facetime with management as a sign of their seriousness and commitment. Handing a potential client off to a BizDev person has killed many deals.
By the time most startups are ready for a bizdev role, they're not really a startup anymore. If you want the startup experience and knowledge, you're going to have to sell yourself in as more than just BizDev -- Project Management, Product Management, PR, Office Operations /Admin, etc -- if there's something more you can add to the team, you'll may be worth the cost.
Also you should think about what you want out of the job -- money , experience, or both. The bulk of startups using a recruiter are somewhere between their SeriesA and SeriesB rounds - so any sort of equity compensation is going to be minimal. You'll get a token stock option ( though the company will try to overstate it ) -- but it's a token; your compensation should be focused on market-rate salary and benefits.