You need VERY low wages for a 9 seater airline.
High US wages are fine for a 50 seater airline, if you run it well.
For a 30 seater airline, it'll be easier somewhere wages aren't really high, like Eastern Europe. It'll be easier again somewhere wages are really, realy low, like Vanuatu. But I think it'd still be doable in the US/UK/etc, provided you found the right airport. You want HQ to preferably be size 3 or less, though could do size 4, and with as many 30+ pax routes to other size 4 or smaller airports inside 300 NM. Maybe somewhere like Rotterdam, Eindhoven, or Brussels South would be good choices if you want to use a high-wage country. Not sure if the US would have a suitable airport, because of the way the demand algorithm works, size 3 to size 3 tends to only have a small demand, though there might be exceptions.