I went back to walmart to pickup the 10w-30 Rotella. It was actually 11.77/gallon, not the $13 I thought it was.
Theres no shelf tag for it, only the 15w-40 but it rang up fine. I don't think its a regularly stocked item there, but I'll be checking it every time I get the chance. I asked the workers, they said no oil in the back whatever they have is on the shelves.
The RTS is plentiful, so theres always a backup option.