I get my oil changed at NTB. No, it's not cheaper, but if you buy tires there, they'll balance and rotate your tires for free every 5K miles. It's cheaper because my tires last longer this way. They do it whether you get your oil changed there or not, but if I don't get my oil changed there, I tend not to get the tires rotated and balanced and they go bald quicker.
And, NTB is bad about the upsell. If you don't know anything about cars, they'll sell you anything and everything you don't need to be worked on. If you don't know anything about cars, or don't have a regular mechanic you trust, stay the hell away from NTB for anything but tires.
I couldn't get cheaper tires anywhere other than NTB because I have 17" wheels. They don't stock them as readily at Sam's or the other cheap places. So, they weren't any less.