Have you tried Price Chopper on N. Oak and Vivion or Sunfresh in Westport? I don't use soybean oil myself, but those two stores have a wide array of oils to choose from (I get my Olive Pomace from Price Chopper). You can always call first if neither of those stores are close to you.
I used to use Crisco, but when they changed their formula a year ago, the soap felt "different." It is also getting so expensive. This at Sams is much harder than Crisco out of the box, and nearly 50% less per pound!