How much should it cost to replace a thermostat housing assembly on a 2004 Mazda6?

Labor rates around this part of Oklahoma have been traditionally some of the lowest in the country but even a local full serve gas station raised their rates to 65 an hour several years back.

Forty-five an hour for a garage seems extremely low and non-profitable but I suppose it might be passable if it’s a small one or two horse operation.