If my goal for my career in Electrical Engineering is purely monetary, where should I stop in terms of education? What are the highest paying options for each degree level?
In general, M.S. and Ph.D. will make about the same, M.Eng. will make slightly less, and B.S. will make less still. But a given person might well make more with the B.S. than they would with the Ph.D., depending on where and how they get the degrees and what they try to do with them.
I am not sure that is a meaningful question. Entrepreneurship, management, and a lateral movement into finance are among the most lucrative options, but they are realistically closed to most people and extremely risky for the rest. But it is not realistic to summarize an entire career field’s options in this way.
How much money you make depends on what you do with the degrees, not the degrees in and of themselves. You could make more with a BA at a wildly successful start-up than a PhD teaching engineering at a university, for example.