I remember hearing the same thing — folks saying you’d get more opportunities once you hit 500. To be honest, that’s sort of a pipe dream. Those jobs do exist, primarily in the survey and skydiving world, but you’d better be ready to move because they are few and far between.
Seems like a Ameriflight hires fairly often for the PNW. Granted, you’ll need some more hours to hit part 135 mins, but that (or Empire or another small 135 cargo operator) may be your best realistic shot.