Repair makes sense for isolated flapper, fill valve, or supply-line issues on a solid, quiet toilet that still flushes well.
Replacement is usually smarter when the bowl or tank is cracked, the toilet rocks because the flange is failed, you’re dealing with repeated clogs on an inefficient model, or a remodel needs a different rough-in or comfort height.
A good install includes inspecting the flange, setting a proper seal, leveling the base, and testing through several flushes. Skipping those steps is how “new” toilets start leaking in a month.
Ask partners for haul-away and whether your shutoff valve should be replaced while the supply is open — old angle stops often seize or drip after disturbance.