NO
I have a shop in my area that I can get in to almost any time and the shop rate varies from as low as $65 to as high as $125. The reason why the shop labor rate changes is because they do not put their top mechanic on a job that only requires an apprentice. For a lube job or tire balance, you get the lower priced mechanic. For basic mechanical work, you may get someone in the mid-range. For a complicated problem, that will need an expert's diagnosis, then you pay top dollar. After the diagnosis is made, the labor rate may change if it is a mundane job to repair.
This shop is always packed and the customers know they will be treated fair. Personally I would avoid any shop that charges their customers top dollar, even if it is the new guy or the old pro that works on your rig.