Toys"R"Us offers the Play-Doh 2-in-1 Sweet Shoppe Cake Mountain Playset for $9.99 plus $5.99 for shipping. (Amazon charges around the same.) That's the lowest price we could find by $6. It features the shop base, bottom cake tier, cake machine with accessories, three cans of Play-Doh, and two cans of Play-Doh Plus.
Walmart offers the Play-Doh Disney Pixar Cars Toolset, model no. B7492, for $4.29. Choose in-store pickup to avoid the $5.99 shipping fee. That's at least $4 less than you'd pay at another local retail store. It includes five jars of Play-Doh, a Lightning McQueen rolling stamper, Mater stamper, gas pump, and roller knife.