Under $500 if you go for the mark 1 versions. And the only drawback is purplish coloring and .5 a stop less stabilization.Don't the Panny 12-35 and 35-100/2.8 offerings kind of fit this need? Pushes the $600 - $800 range a bit.
Also Panasonic 12-60mm f2.8-4 is relatively cheap since it was a kit lens once.
There are a dozen+ awesome under $500 primes
And really, the "high grade" 4/3 stuff was never that cheap. It's cheap because 4/3 is a dead system and they don't adapt to much. But they were expensive when current.