Let's use a simple example, customer clicks on item let's use the t-shirt example

T-Shirt Cost $10

Color: If you choose Red Cost  + $5

Size : If you choose Large Cost + $5

Total $20
So I know how to do that, with drop down boxes etc

What if I want to have it so if I choose the Color Black which is also $5, but large then becomes $7

So If I choose a black t-shirt, that's large
my new total will be $22

Is this possible?
Thanks