Question about padding on shop estimates

I recently took in a Ford Fusion hybrid into a local dealer to estimate repairing the transmission. The issue is related to a bearing failure that is pretty well documented on these CVTs and Ford has issued several bulletins about it.

In fact, there is a recall and this transmission has already been replaced under that same recall several years ago. Unfortunately, I am beyond the warranty period for the replacement, so now having to repair on my own dime.

My question is about estimates. The bulletin clearly details the procedure and estimates about 13 hours for the work. However, the dealer estimates 18 hours of work. After asking about the difference, they started that the always quote 40% on top of the estimates for all repairs. Is this common?

Also, I found it peculiar that when I declined the repair they provided my paperwork but were adamant that i leave behind the print out of the service bulletin on which they had notes the 18 hours. This was stranger to me because it is publicly available information.