I don't know if this is typical, but assuming an instrutment rating
costs $5-6000 to get working the $/effective knot here might be a pretty
good number. So pilots who fly both IFR and VFR, is that experience
typical?

Certainly not in case of non-turbo'd airplanes in the West... VFR is
almost always more efficient, routing-wise. However, I agree IFR tends
to be a lot easier in busy class-B areas.