I used AMEX $30 off deal along with the DeWalt $25 off deal. You need to activate AMEX offer at your Amazon account; it shows at the top of the page or bottom when I am shopping. You need to use your AMEX card with some points applied (I used 1 cent rewards). DeWalt discount is automatically applied.
The following link shows reward rules and the activation link; I don't know if this would work.
Shipping & Handling:
Total before tax:
Estimated tax to be collected: