Amazon has the 15.25oz Duncan Hines Cake Mix (Classic Yellow) for $0.99 - 5% off with Subscribe & Save (can cancel at any time) = $0.94 with free shipping on $35+ or with Prime.

• 18.3oz DH Chewy Fudge Brownie Mix for $1.46
• 18.2oz DH Dark Chocolate Fudge Brownie Mix for $1.54