I've had to shop the different WalMarts. We've only got a good selection of oils at one of the four within 40-miles of me. But one of the others carries the 20W50 in 5qt containers. Gotta shop around...
I use Mobil 1 exclusively. Mostly the Extended Performance 15,000 mi. oil which is still under $30 here. I change the filter out as it approaches 7,000 mi. and the oil @ 13K. Never had any trouble. No oil consumption between changes in any of my three regularly used vehicles. In order of age, the 96 4x4 has 219,000mi. The little 02 DD has 181K, and the wifes 07 suv that uses the ultra thin 5W20 is up to 101K mi. already. No troubles, always Mobil 1.
Thing I wonder is, if synthetic really needs to be changed at 5,000 miles even. It doesn't smell bad, doesn't look burnt. It's not the sort of expensive lesson I want to learn by experience, but I mostly run the 15,000 mi oil and wonder how really different they could be? A label and two dollars?