Shopping list help - add checkmarks with formula's? how to find % off total

[wickedgoodsavings]

I have been getting pretty into extreme couponing lately, and Ive been working on a spreadsheet that is becoming quite helpful when planning my shopping trips. Here is what I'm working with at this point. This is all working properly when numbers are entered into it by the way.

So here is what I want to do:

Insert new columns with checkmarks for double coupons and buy 1 get one free. Right now the 2 rows at the bottom have a formula of D/2 to show the correct amont for B1G1F. but rather than having to add new rows containing the formula, I'd like to have a checkbox in every row that would change the total in column D when checked. It's the same idea for the double coupons. if checked, the total in column F would double. Is this even possible to do?

I also want to figure out how to add a row at the very bottom where you enter a % off, and It will show how much the discount is and a new total.

 

[sheetspread]

Use an if statement to print the total if no Xs are marked in another cell (if you really want checkboxes that can be done also) otherwise the total * 2. You can also multiply the total by whatever percent, example *(1-.2) for 20% off.