As a "medium-cost" compromise:
. . . Find a jeweler's supply store, and get a "10x triplet diamond loupe".
Like these:
Loupes | Magnifiers | Watch Maker’s Loupes | Head Magnifiers
They're pretty well free of color fringing, and the field is pretty flat. The Bausch & Lomb 10x is plenty good enough, and probably so is the NJS-branded loupe. [My own loupe is unbranded, bought from a local guy who teaches gemology.]
It's not as good as a microscope, but you get a good sense of what the edge is like. If there's enough trouble to require a bevel reset, you'll see it.
Charles