Percentage Pricing on Attributes

Hi I have a site that has a variety of attribute options to choose from.

The Products have 5 options to choose from in the first set of attributes which are set at standard prices as follows:

Product 1

Attribute Set 1 - option1=£300.00, option2=£350.00, option3=£400.00

Then a set of attributes underneath these that apply 20% of the price on top using Price Factor: 1.2 Offset: 1.0

I need the 20% to be added to whichever option is selected in Attribute Set 1 - so 300.00 + 20%, 350.00 + 20%, 400.00 + 20% when they select any of the attributes beneath Attribute set 1.

Currently the Price Factor : Offset is applying 20% to the lowest price (base price) only when I need it to add 20% to whatever option is selected in Attribute Set 1.

Can anybody shed any light on how I would allow attributes to apply a percentage of the price to any of the options selected in Attribute set 1 instead of only applying it to the base price?

So if option 2 = £350.00 was selected it would still apply 20% on top of £350.00 (£70.00), instead of adding 20% of option 1 = £300.00 (£60.00) on to £350.00.

What you are describing is "Dependent attributes" and ZenCart does not have any support for them

Kobra I actually have something working after finding this thread http://www.zen-cart.com/showthread.php?185921-Percentage-Increase-On-Attribute-Price&p=1159692#post1159692

Which states to change this

$added_charge = zen_get_attributes_price_factor($chk_price, $chk_special, $attribute_price->fields['attributes_price_factor'], $attribute_price->fields['attributes_price_factor_offset']);

to this

$added_charge = zen_get_attributes_price_factor($attributes_price, $chk_special, $attribute_price->fields['attributes_price_factor'], $attribute_price->fields['attributes_price_factor_offset']);

And it works to a degree. The calculations are done correctly all the way through the cart process exactly how I want them, apart from I cannot find how to update the sub total in the shopping cart, that still displays the sub total as Base Price + Attribute Price (not percentage of attribute price).

Which file controls what is displayed in the sub total inside tpl_shopping_cart_default.php? If I can get the sub total to add together prices that are calculated with the changed line of code above then it will work exact to how I want it.

Just thought I'd edit this, $added_charge = zen_get_attributes_price_factor($chk_price, $chk_special, $attribute_price->fields['attributes_price_factor'], $attribute_price->fields['attributes_price_factor_offset']);

can be found in classes/shopping_cart.php not as stated above