I tried this on one person. Here's how it rolled.
3-5 minutes to listen to issue , ask questions about basics (version, errors).
State that it is $x to correct paid in advance by credit card.
Response:
""Is that no matter if it only takes a minute to fix""
Me: Yes
""I will check with my manager"" (Translation: No)
These folks were on 3.4 of MAS90.
I created a PDF for charge authorization as partial defense against someone wanting to charge back.
I don't expect anyone to take it but I think it will be a lot faster getting tire kickers off the phone ( no money or intent to pay ).