I would still place the items on ebay. Charge actual shipping charges, and put the starting bid at the cost of the auction.
Clearly note in the auction that any bid above starting will be donated to your favorite charity.
Optionally, the bid amount could go towards covering the shipping costs, and any excess would be donated to charity.
This eliminates the possibility of someone re-selling them for profit, and can support your favorite charity at the same time.
-Jeff
