AVG price of oil in 2006= $61.37
AVG price of oil in 2008= $99.65
Polyester resin is derived from petroleum. Cross bars are smelted using petroleum. Tramps and sails are made with petroleum. Not to mention transporting this stuff all around the country/ world.
Oil should have been $64.28 in 2008 according to the posted calculator. I feel cheated

J