Amazon offers Prime members the Life is Good Shoulder Bag with Detachable Strap
in Blue for $14.24
with free shipping
. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $5.58.) That's $36 off list and the lowest total price we could find. It features dual shoulder straps, removable/adjustable cross strap, exterior zippered pockets, and two interior pockets.