Hi,
I think the better way is to export the report as an Excel file and use macro formulas in Excel to search the price into the list (or use Allplan BCM !...).
Adding the price could be done by using a personal attribute on each object.
Then, you prepare a wizard with all your objects, and in each obejct an attribute is adding with the unit price. You have to modify a report to get this kind of formula : Length * My_Price or Height * My_Price or Volum * My_Price.
:-)