Good deals on Colman's Mustard at Amazon with Manager's Special temporary price reduction.  Here is a screenshot for your reference.  Shipping is $0.99, or free on orders over $25.  There is a special subscription to save an additional 15% by receiving the products at a regular interval and shipping is free with no minimum.  Note that the subscription can also be canceled at any time with no obligation.

• Colman's Dry Mustard, 2-Ounce Canister (6-Pack) for $11.20
• Colman's Dry Mustard 4-Ounce Tins (4-Pack) for $13.17