Today - Mamasource has these cute reusable bags on sale. Get a $20 voucher for only $10 and the voucher is good towards shipping!
The above Luxe Tote is $14.50 and with the flate rate $4.99 shipping, you can get it for the $10 price of the voucher shipped!
They also have surplus bags for only $10.
Go here to get all the details.