The winning bidder will pay full postage for the item with most expensive postage  +    50% postage discount for each other item.

(For example: John won 3 items from us, the postage for these 3 items are $15, $10, $12==>John will need to pay the most expensive postage $15 + $5(50% off  $10)+ $6(50% off  $12) =$26 in total postage.  John  saves $11 postage & handling on these 3 items he won.)