Tax + Combination Question

[wakasm]

I have a shop. I have a product that has a wholesale price of $15 and a retail price of $40.

However, the way I set up the price is with combinations.

Combination 1 = $40 (No price adjustment)
Combination 2 = $30 ($-10 - because it's made of cheaper material)

We tax one state. Let's pretend that tax is 10%

Currently, no matter which combination they choose, the tax = $4 (because the base price is $40) for either combination.

How can I set-up Prestashop so that the combinations have the correct price for the FINAL price, after the adjustment? In this case...

Combination 1 = $40 + $4 tax (@10%)
Combination 2 = $30 + $3 tax (@10%)

Thanks!

[wakasm]

Any ideas - Client is getting ancy over it. I'm hoping it's a setting I'm missing and not something I have to code. Search has not helped me find a solution so far.

[wakasm]

[Edit] Accidental double post sorry

[wakasm]

/Bumpity? - Not sure if Bumps are allowed, but still a very needed answer!

[wakasm]

Please?

I tried this thread (and even bought the $20 mod) but was unable to fix this issue.

http://www.prestashop.com/forums/viewthread/27951/


I believe this is a start to my needed solution - http://www.prestashop.com/forums/viewthread/67971/development/combinations_and_tax

but I can't figure out the product.js part.

It's really a problem.