Basically you pay 0.5 BTC for my services of loading the card and sending it... but you give me the amount you want loaded on to it. I have created a screen shot that illistrates where you should type in the value for how much the card should be loaded. I made everything super simple as far as check out goes.
The minimum amount you can store on a godaddy gift card is $2 so you can see that the Cheaper In Bitcoins product page automatically fills in the lowest minimum which is 0.5BTC in this case of the below screen shot.
Here is what it will look like in your cart if you put a value of 7 BTC on your godaddy card.