Using latest stable: 2.0.6 and Joomla! 1.7
The price (basePrice), tax (taxAmount) and discount (discountAmount) per product don't show in the cart.
Tracing the problem lead me to administrator/com_virtuemart/helpers/currencydisplay.php, function createPriceDiv.
The price was calculated but it was not formatted since the $this->_priceConfig[$name][0] as empty, and around line 382 the condition
if(!empty($this->_priceConfig[$name][0])){
was false, making the formating and the price value return impossible.
Removing this condition worked for me, since in the beggining of the function there's a fallback, but I don't know if this is the correct fix.