Back in the day, most regionals were 135. I never looked into the check hauler 135's because I wanted to go airline, but from what I remember, it was build to 1500tt at least, get hired by single pilot 135 ops, build up to 2500tt for the regionals and make $19k per year, after PFT. That pay didn't change for almost 20 years, sadly.
@Derg @MikeD and whoever else was around back in the "good old days" have anything else they remember?
That was back when they were known as commuter airlines. The pay didn’t improve much when they became regionals and moved into the Jet age