Painting/Weatherproofing External Wood Window Frames

First time poster here — we are buying a coop in Park Slope, not landmarked, and it has old wood windows. The frames/casing (the part touching the building that the window sits in) are in need of weatherproofing and painting. Could be true of all 9 windows. Windows are functioning. Switching to aluminum/vinyl is not currently an option. Does anyone know how much that typically costs in broad strokes? Can workers do this without scaffolding (apt is on an upper floor). Any info appreciated!