We're not going to hand you a number here that doesn't hold up once a tech is standing at the door, so instead: the cost drivers on a commercial job in Great Falls are the door size, the spring count (single vs. double torsion), whether the opener needs safety-sensor work to meet current standard, and whether the part is one we carry versus one we order.
Given the household income in this part of the service area runs well above the wider area's median of $149,344, we do see more requests here for higher-spec insulated steel doors and quieter belt-drive commercial operators, rather than the base models. That's a choice, not a requirement, but it moves the number.
The travel itself, 11 miles from Chantilly, isn't a separate line item, but it is why a return trip for a missing part costs you time more than it costs you money. Ask for the diagnosis in writing before any repair starts, so you know exactly what's driving the total.