For me its closer to $25. Wally's Super Tech 0W-20 and the corresponding Purolater Filter. Tried using my wife's stock of Mobil 1 (for her SUV) but Super Tech does the job well enough.
As for Mr. Tire, they do have to make a profit. Using bulk 0W-20, a generic filter plus 1 hour labor, they'll make a minimum of $45 from the $100 quote. Add fixed overhead to that, they'll net $25. That's decent enough.

 

The maintenance minder has nothing to do with oil consumption. You need to check the oil level once in a while. Mine uses a quart every 5000 to 6000 miles. The maintenance minder tells you the % of the mileage left until your car needs an oil change and other maintenance. Mine goes from 100% to 0% in around 11,000 miles.

 

I follow the Maintenance Minder which means I'm changing oil around 11K-12K miles. I use regular (non-synthetic) 5W-20. I think synthetic is a waste of money and just another ploy to get people to open their wallets wider.

I think the combination of tighter engines (less combustion byproducts making it past the rings and contaminating the oil) and much better oil technology make all of the difference. The oil in my '09 Fit after 11K looks much, much cleaner than oil in my 70's and 80's vintages cars after only 3K-4K miles.

See this article at Edmunds.com titled "Stop Changing Your Oil" for further explanation.

I'm a firm believer that you can follow the owner's manual. Which says use a premium-grade 5W-20 and change the oil when the Maintenance Minder tells you to. The "every 3,000 mile" logic makes no sense for modern engines.