Hittime HK via eBay offers the Inflatable Travel Pillow Neck U Rest Compact AirCushion
in a randomly chosen color for $1.38
with free shipping
. That's tied with our mention from two weeks ago as the lowest total price we've seen for such a pillow. (It's also the best we could find by $2, aside from the price below.) Expect this item to take two to three weeks to arrive.
A close price: Lucky Electronics via Amazon has a similar item for $1.75 with free shipping.