Galvanized fails at the threads.

June sweats copper. She opens the plaster at the fittings. She does not strip a whole wall to replace a riser that is rotten only at the valves, unless the pipe between those valves is orange when she cuts it. Then the wall opens further, and she calls before she keeps cutting.

Kitchens and baths come first when the budget is the limit. The whole house comes when every valve weeps. She prices the one you described, and she says out loud if the next opening is going to change that price.

PEX is the conversation for a house with no crawl and a budget that will not carry copper. She will tell you which material is on the estimate. The estimate does not switch materials in the wall.

Valves that have not moved in years get replaced while the wall is open. Leaving a seized stop behind new pipe is how the next leak starts. Fixture stops are the same idea, one floor down.