Jeep Repair: check engine light, firestone, scanners

Question
Why do some places, like Firestone, etc., charge $89.99 for a check engine light determination?

That seems ridiculous. It takes a minute or so to do.

Also, Firestone charges about $20 for an inspection, in the event you have something wrong with your vehicle but have no idea what it is.

If that's the case, why would anyone pay $90 to get their check engine light checked if they can get the problem determined by a $20 inspection?

I'm guessing the inspection is not as comprehensive as determining the cause of the check engine light.

Answer
things worth your time are most of the time not free.
The scanners that they have are not free or cheap  they can run from 1000 to 5000
Just about every place does it   also  the techs dont work for free either   do U want to do a job for free at your work?