There is a hosting plan configured as shown below, where Prom is the 50% setup discount promotion.
Shopping cart shows the hosting plan price like
The discount is first included in Setup fee and then is highlighted as a separate string, so that a shop visitor can suggest that the price is calculated as $5 + $5 -$5 = $10?
There is the software issue PBAS-30183 to show full prices and then a discount so that the total price formation is more clear to store visitors. It was implemented in OBAS 4.5.6 release.
Please upgrade to 4.5.6 as described in How to upgrade OBAS system to the latest available version.