I think at 43, more organizations will be looking at your experience rather than anything else.

My DH did his MBA at 28, and his employer paid for it. As he hasn't left that employer or looked for work elsewhere, I can't really say if it has helped in that regard, but it has definitely meant that he has been able to work his way up much higher in the company.
He also had a degree, but for some reason, his employer thought an MBA would be very valuable. He's a Project Manager at an IT company.

IMO, if you're paying for it yourself, it's a lot of money (although tax deductible), and a big time commitment. I'd keep going with Certs focusing in the direction you want to go if I were you. As someone said earlier, an MBA is very broad and doesn't focus too much on a particular area.