Walmart offers the Wilton Decorating Coupler 4-Pack, model no. 411-1989, for $2. (Amazon has it for the same with free shipping for Prime members.) Opt for in-store pickup to dodge the $4.97 shipping fee. That's the lowest price we could find by $4, excluding other Amazon vendors. These couplers allow you to change frosting tips without swapping bags and are compatible with most types of frosting.