Great question, and you're already thinking like an MBA. This is actually such a common question, that a couple of different websites and news publications have done the analysis for us.
Business insider explains:
<span style="color: rgb(17, 21, 22);">We took a look at our list of the </span>50 best business schools in the world<span style="color: rgb(17, 21, 22);">and re-evaluated them on a ratio of starting salary to tuition to determine which schools give you the best bang for your buck. The higher the starting salary and lower the tuition and fees, the better the school fared on this ranking.</span>
<span style="color: rgb(17, 21, 22);">After doing that, the best grad school bang for your buck is Brigham Young. The next couple are outside of the country, so if that's an option, go for it! The next US school they consider a great value is Texas A&M's. Note, though, that they admit that they excluded in-state tuition options. You should check your state schools to see how much less expensive it might be for you to attend, than to go to a school outside your home state. Be sure to be critical of their career placement statistics (like salary after graduating) and rankings in magazines like US News and World Report.</span>
<span style="color: rgb(17, 21, 22);">That said, I went to a pretty mid-ranked part-time program, and felt like it was an outstanding education for the money.</span>
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