I don't have book time in the IT industry.
Don't know of any industry that has "book time", but I also have not worked.
You can either allow over bidding, or have book time, can't have the best of both worlds and choose whatever screws the customer over more imo.
Book time on itself is not the worst thing ever, and over bidding because a job sucks or is not interested is not terrible either, when you combine both is when it really is insane.
These are car dealerships certified from the manufacture to do work on X Y Z branded cars with set rates, except when they don't wanna and ignore the listed rate. When you are getting charged over MSRP you are told, they can't hide MSRP and then you know you are getting screwed. Here there is a guy saying it's 3 days of work for a 1 day job, the customer doesn't know he is getting screwed "by the book"