How much extra should high-altitude window installation cost?

I’m comparing replacement-window quotes for a mountain home and trying to separate legitimate altitude-related work from ordinary window and labor costs. The house is at about [elevation] feet, with cold winters, strong sun, and [wind/snow exposure]. There are [number] openings, mostly around [approximate sizes], and access is [straightforward/difficult because of slope, scaffolding, or multiple stories].

The quotes need to clearly show whether they include:

- Insert or full-frame installation
- Removal and disposal of the existing windows
- New exterior flashing and water-management details
- Interior and exterior trim replacement
- Repairs to rough openings, siding, stucco, or interior drywall
- Any special access, scaffolding, travel, or weather-protection costs

I’m not assuming altitude alone requires a special window or installation method. I’m more concerned about vague line items such as a “high-altitude surcharge.” Which parts of a mountain installation have actually increased your cost: access, wind exposure, flashing, short weather windows, or something else? What level of detail would you expect in a quote so the window price, normal labor, and genuinely site-specific costs are easy to separate?