Option that adds a percentage to total.

I need functionality that will allow me to add a product option that will add a specified percentage to the total of all other options.

Lets say I'm selling t-shirts and they choose these options:

Color: green = +$10
Size : XXXXL = +17
quantity: 10 = +7
and then I want another option that is dependent on the previous options and therefore I want to make it a percentage:

Stain protection: + 10%

OR

irregulars: -10%

Please quote price for this project. I am going to be using Q's extension: product price update" so you can use that to help implement this.

I have a deadline on this project, so I need your price quote by midnight May 12th, with work to be completed within 2 weeks. Thanks!

option plus redux supports percentage based option pricing. So you can set an option to be 10% of the product price

Q, this is what you said previously on the topic discussing your extension:

Qphoria wrote:I have one that lets you set the price of options based on a percentage of the main product price, but not on other options. This would be quite difficult because the values would need to be calculated based on user selections using ajax callbacks to do the math

will the other extension you just suggested allow it to be a percentage of the total of all previous options selected as I need?