i am new to magento and i have referred too much magento tutorials for configurable product with associated product and super attribute but still my issue is not fixed,so i have asked this question.please i need help.

i wants to make a configurable product like, tshirts having 2 attributes as color and size, tshirt product with $20 with size 28,30,32 having color red,green,blue but i wants to make different price for only one associated product tshirt with size 30 having color blue as $25(+ $5 more than any other combinations). how can i do this??

i have created all combinations of associated products for attribute color and size and i have also change the price of that assoiciated product tshirt size-30 having color-blue as $25 but it not showing in store it shows price of configueable product. please help...