Repairing stone veneer or redoing it
If a few stones have come loose or some joints have cracked, we can usually reset and repoint those spots without touching the rest. When stones are dropping off in patches, or the wall behind stays damp or stained, water has likely gotten in, and a patch just hides it. In that case I'd rather take the section down to the wall, find out why, and redo it with a proper barrier. How far that goes, you'll only know once it's open.
What shapes the cost of stone veneer
Square footage sets the starting point, and the stone comes next, since natural thin stone usually costs more than manufactured. Wall prep can swing it a lot, from a good cleaning to real repairs or a rebuild. Outside corners, sills, caps and openings take cutting and trim pieces, tall walls need scaffolding, and a drainage layer behind the stone adds material and labor. A permit and its inspections add some too when the job needs one.