Rekeying costs roughly $20–$35 per lock. Replacement costs $95–$180 per door. On a typical 3-door home that's $150 vs $500 — a rekey saves you about 65%.
Rekey when: your locks are less than 10 years old, still turn smoothly, and you just want old keys to stop working (new home, lost key, ex-tenant, contractor cleanup).
Replace when: the hardware is corroded or sticky, you want to upgrade to smart or high-security (Medeco, Mul-T-Lock), or you're mixing brands and want one key for everything.
The 60-second decision: turn the key. If it wobbles, sticks, or the deadbolt drags, the lock is worn out — replace. If it works fine and you just don't trust who has copies, rekey.
Both jobs take under an hour for a whole house. We carry Kwikset, Schlage, and Baldwin cylinders on the van so you don't wait on a hardware run.