Costco sells them for $20 if you have one close by. The only downside is that they only have the bright neon colored ones left since all the "good" colors are gone. They used to sell them online but they're all gone.
At Shoebuy.com, input SALE as a promotional code for 20% off. PLUS you can register as a new member and get an additional 10% off! All the other codes above don't work...