I just called Perkins oil and here are the prices at the Aeroshell booth this year:
W100 $68.40 + Tax
W100+ $73.29 + Tax
That looks like a great deal to me if you can afford the weight on the trip home.
airplaneoil.com:
W100 $70.00 + $17.04 Shipping
W100+ $74.00 + $17.04 Shipping
Aircraft Spruce OSH Pickup
W100 $77.85 + Tax
W100+ $86.80 + Tax