I'm not wealthy by any means, and I've managed to read Ehrman's books, usually by checking them out of libraries where they are all but universally available. Ehrman is an important scholar in the field of New Testament textual analysis - acknowledged as one of the top historians in that field, even by historian peers who dispute some of his conclusions.

Multiple attestation (as a careful tool, not a sledgehammer) is an important way of evaluating historical evidence. I'm aware of no professional historians (outside of fundamentalist Christian circles) who wields the tool to somehow "prove" the supernatural.

You might be more likely to find that sort thing in Bible colleges and seminaries, but actual historians like Ehrman tend to stick to their field of expertise.