I just ordered 2 cases of Shell aviation oil from my local oil distributor. It came out to at least $10 cheaper(per case) than buying off the net, once you factor in shipping verses sales tax & all. The guy was rather helpful & says he gets shipments from the supply truck every Monday(or every other?).
That should keep me in oil well into next Summer. The plane(Warrior) is in for annual now & that includes an oil change. I use 15-50 in the winter & 100+ in the warmer months.