I'd have to say that I'm in the opposite camp...the "Don't waste your money because you start at the bottom anyway" camp.
I have a BA, and the folks who have worked under me that have a Master's are not willing to work hard. They spent that energy and 2 or 3 years getting a degree, and they still have to make coffee and sharpen pencils at the end of it. No matter what you come out with, you start at the bottom.
If your degree is in something else completely, and you have no theatre background at all, then having a masters degree that teaches you something new is worthwhile. But if you have a theatre degree, then go work. A masters is only good for dramaturgy and teaching college. Besides, in 10 years, you might want a masters in business or artistic administration instead anyway.
My advice is to find internships (paid or unpaid) and get out there.
Good luck, whatever choice you make.