Gift cards that are sold and need to be sent through the mail should be handled with special attention.
Always go inside of the postal office and have the mail weighed for proper postage and sent with tracking information.
Never toss them in a blue postal box to be mixed with regular mail.
Gift cards can get caught in normal mail machine rollers, destroyed and ultimately tossed according to USPS.
Always take a photograph of the gift card, and write down the gift card number, pin, any and all information to help track the gift card if it should become lost in the mail.
Keep receipts if the gift card was purchased to help put a stop on the card if it is missing.
Keep toll free numbers, and any information if the card was won prior to the sale to help contact the issuer if lost or stolen.
Pay the seller only after you have received the gift cards in the mail or only after it has been proven to you with tracking that the cards have been mailed.
If you buy something from someone using Paypal and "send money to a friend", you have no guarantee to get your money refunded. A friend is not a seller. You did not buy anything. You sent money to someone.
Hopefully they will honor the sale but this is a risky trade indeed.
Even a seller with the best intentions can cause a loss to themselves and the buyer if they don't take the necessary steps to provide tracking.
Missing mail without a tracking number is like a needle in a haystack.