Regional jets cost a LOT more than that per hour to operate...

First hour fuel burn is what, 3000lbs/450gal? At $3/gal (and I think many airlines are paying more than that) that's $1350 just for fuel...before you consider the amortized cost of engines, APU, parts, maintenance labor, and lease/debt service.

But your point that crew costs are, by comparison, insignificant on a per-hour basis is valid.