Don:
Estimates are a part of doing business.
Our policy is estimates are "free"
We do primarilly commercial work, and don't get a lot of residential estimate calls.
"How much to install a paddle fan"?
The situation you referenced was a bummer alright; you did the leg work, and were 100% upfront in stating "no permit was needed"
I probably would have told the "customer", we would handle it as a service call, with the hourly rates, materials costs, and any permit fees billed at completion.
HotLine1
John