Set total cart amout

Question

If the user didn't buy anything ever, at the first time he gets a 20% tax of total shopping cart amount. I'm newbie in Drupal and can't understand how to implement it. Say I'll do checking for first order (I imagine how), but I can't find how to change total cart amount without changing every item price.

I hope you can help me :)

Answer 1

The trick to this is to create a discount. Force users to register before purchasing an item and than check the order history of a user at checkout. If the user has no order history at checkout than give him a 20% discount, if not than charge retail price.

This can be achieved with

1. http://drupal.org/project/commerce_checkout_login
2. And either a custom module or rules