I used to work for Kraft foods at their edible oil refinery in Buena Park, CA. Soy oil is the cheapest grade of cooking oil you can get. Anything marked Veg oil is soy. Corn or sunflower are good alternatives.
We would on rare occasions refine a batch of peanut oil, very high quality stuff. When we'd run a batch you'd see a line of guys getting "samples" from the holding tank it was in.
22.5 WSM, 22.5 OTG, 1992 Smokey Joe