How should I compare a faucet repair quote with replacement labor?

I’m trying to decide whether a leaking, stiff single-handle kitchen faucet is worth repairing or whether replacement makes more sense. The faucet still has water flow, but the handle is increasingly difficult to move and there’s a drip around the spout after shutoff.

For comparing estimates, should I ask the plumber to separate:

- Diagnosis or service-call cost
- Cartridge, seals, or other parts
- Repair or replacement labor
- Faucet removal and disposal
- Leak testing afterward

I’m also unsure how much the quote can change if the shutoff valves don’t operate smoothly, or if the supply connections are hard to reach under the sink. Would those conditions normally be checked and listed before quoting the labor?

What’s the most useful single question to ask so I can tell whether a repair quote is reasonable compared with a full replacement installation?