Hi,
We turned off displaying the labeling on the GridView and MultiGridView on purpose because, simply, there is no space to display them. Grids are already small and there is add-to-cart button on the right hand side. That would be against physics to fit them all into that tiny area.
(The price labels are displayed on the ListView only if you enable labeling via Virtuemart Configuration > Price)
If you have to display prices with/without tax (required by law). Then, you may have to change things a bit. For instance, in the gridView card; take the "add to cart" button from right-hand-side and put it in the bottom. So, you will have more space to display price labels; then you can re-enable displaying "labels" from this PHP file:
/templates/YOUR_TEMPLATE/html/com_virutemart/sublayouts/prices.php. You may also consider giving text-align:center to price elements, so the grids will look better (i suppose, but it is up to you thoguh)
Since this is considered as 100% custom modifications
(because you want to change how the things work/look) and unfortunately we don't provide free support or step-by-step instructions for custom coding modifications.
You may purchase premium support:
www.flexiblewebdesign.com/premium-support
and let us take care this modification for you directly on your website though.
Regards.
Support