why do you think a jetbox is cheaper to run than a 500 ?
Parts: widely available new & used (many more airframes out there)
Service: everyone knows how to fix a 206; the ubiquitous turbine helo
Training: Many sources
Insurance: Guessing but likely less expensive for equivalent coverage due to 206 excellent safety record.
The 206 is sort of like a King Air 90 in the fixed wing world. A very well known quantity with few vices.