I have a Joomla / Virtuemart installation. We have two user groups (default, and [url removed, login to view]). Most of the modification has already been done by another company. There is just one variable that needs to be modified.
All products on our site are a fixed 20% off. for example, our main product is $44.9625. They are automatically given a 20% discount so it is $35.97.
If they do not purchase the minimum amount ($300), we take away the 20% discount (Discounted Price * 1.25). All this has been updated up until the confirmation page. The only thing that needs to be changed is a couple of variable displays on the confirmation page and in the confirmation email.
I've found that these variables that are wrong are being pulled from 'order_total'.
Order total is actually wrong. However, the correct amount is being charged to the credit card and this db field is only used for display.
So, this field in the database needs to be recalced during the checkout process.
This would fix everything. For someone that has a good knowledge of PHP and MySql, this could take under an hour.
A screen shot of the variable that needs to be changed is included.