ATM, the tax management is going to the right way. Adding a tax on the end of the order by calculating line items is the way to go. Why ?

• Because ou have to manage all your prices excluding taxes, when you calculate your turnover, your commercial margin etc.... all is calculate excluding taxes
• If you apply some discounts on your order, they have to be applied on product excluding taxes, this is the law in europe (don't know in australia)
• When you have a tax, you have to show the subtotal excluding tax, then the tax, and then the total including tax. And the current tax module do it very well

So I think showing a tax including price is just a display issue for the product page.

There is only one critical problem with taxes and ubercart ATM, it's the way the subtotal is calculated on the checkout page. It is calculated by adding all product line * product quantity in the cart.

With this way, if you want to show your product prices with taxes on product page, you have to make the reverse calculation on checkout page to return to product prices without tax. If you don't do that, the dirst subtotal will be displayed with tax.

So, the things that ubercart have to do is to calculate the first subtotal line item differently depending on your configuration about tax display on product page if you show prices excluding taxes, make the actual calculation, but if you show prices including prices, the subtotal have to add all product prices includding taxes and then, remove the amount of taxes, this is simple, but it will correct 2 problems :

• Bring the possibility to show a cart with product including prices on checkout page, which is more user friendly
• Avoir rounding problems
• Make ubercart european friendly