I say, when a good deal comes along and it's posted right here in front of our noses, you'd be silly not to think twice about it, evaluate other options and oil brand choices at the preset time and quickly make a purchase while you can.
IMO, oil prices will just keep rising. Mobil 1 in 5qt jugs is nearing $32 dollars in all my Walmarts in Jacksonville, Florida, so the rising cost is headed your way and with the current world situation, oil will only keep rising. I say, better stock up on ANY awesome deal because in a few years when M1 will not be found for less then $10 a quart, you'll be happy you stocked up @ $5/qt when you did and car maintenance will be that much cheaper. Plus you could sell some off if needed and make a buck / get your money back during a hard time.
That's how i look at it and have a growing stash almost weekly. You just never know what tomorrow will bring...