Custom shipping in Magento

I have created a website in Magento. It is working fine, but I want to define custom shipping.

For example:

• I have two types of product: A and B.
• If the user selects A, then shipping will be $5 to the US, and $8 elsewhere.
• If the user selects one A and one B, then shipping will be开发者_运维问答 $5 to the US, and 8 elsewhere.
• If the user selects one A and one B then shipping will be $4 to the US, and $7 elsewhere.

I have taken help from this article, but I need to modify this:

Magento: Two flat rate Shipping Rates based on weight

There are a few ways of achieving this, but you are on the right track with that article. The trick is pulling in all the data you need to make the calculations. I would likely just get a cheap plugin that handles this for you. This will do the trick in letting you create custom rates based on combinations of product, destination, price, weight, etc.

http://www.magentocommerce.com/magento-connect/catalog/product/view/id/17930/