As a store owner, security ranks high on my list of concerns. After getting screwed by my neighborhood locksmith (borrowed an item and refused to return it or pay for it) and understandably fearing my keys might have been compromised (he once cut me a pair of replacement keys and could've secretly kept a spare), I resolved to change my locks.
A colleague suggested I go for the Medeco brand, which while much more expensive is also much more secure.
After I called in, the owner came to see me and he gave me a free estimate. After shopping around some more, I found that he had the best deal and gave him the okay.
While I wanted to change both the inner and outer locks, he rightfully pointed out that changing only the outer lock was unnecessary in my case. I could still keep my inner lock without risk. A true professional, he doesn't sell people stuff they don't need.
Definitely going to recommend him.