I'm trying to create a sub total cart using jQuery.

I create a pen which you can see here:   SubTotal with jQuery

Although it seems to be working but I'm not happy with the code. One big issue is that because I want to have the cost, subTotal and the Total-Cost all calculated when you first open the page, I have to repeat the same code once inside the document ready and once after click on + and - sign to increase or decrease the quantity.

Could you please help me to improve my code?

How can I change the jQuery code to make it more professional?

Thanks