Because the mechanic is not going to get most of that 14.50. To use some easier to figure numbers consider the following.
The shop has a 100 dollar per flat rate hour labor rate.
The shop charges .2 hours (12 minutes) for a filter change which means 20 dollars total labor charged by the shop.
The mechanic makes 25 per flat rate hour let’s say.
The mechanic gets .2 hours for that air filter job which means the mechanic earns 5 bucks for performing that service.
That .2 hours includes flagging in on the job, finding the car in the lot, bringing it into the shop, standing at the parts counter waiting…, installing the filter, running the car back out, flagging off the job, and turning in the paperwork.
There’s more time spent on the bureaucracy than the actual job itself.
One time I went to work for a large multi-line dealer and several mechanics there told me the first day that my biggest problem was actually getting someone in the parts department to hand a part over. They were right.
Seven people in the parts department and getting an oil filter and 5 quarts of oil was a 15-20 minute job by itself. Oil changes paid .2 hours so the mechanic is in the red before even leaving the parts counter.