After getting the Smartshake shaker this afternoon.. had a look around Vitacost and found ON 100% whey to be very cheap :)
Normally I get the 10lb ON whey in store for $140+.
With referral bonus, the 1lb comes down to $8.61USD shipped, which I think is a really great price!
2lb is also available but comes to around $19.
My referral link:
Simply create an account and the discount code will be sent to your email after a min or 2.
Every order also comes with 2 free samples! ON whey is available too :)