Triple Combo box

Hello, I need TRIPLE combo box to be written for my site: [login to view URL] ( please note current solution is not what we need.) I need customer to select Size ( various price) and then Colours (no price) and then for only 4 colour types i need additional 25% (does not have to be percentage - can be numbers for each size) extra to be counted to a total. I know its complicated but please not it can je javascript or php or both. I will describe it in more detail.