Am I missing something

Ok, I was on eBay tonight. (when am I not, I know). I needed to go checkout something at Walmart. Instead of typing it in the address bar i accidentally typed it into the eBay search. There were auctions for walmart gift cards and people were spending more than what the gift card was worth. I don't get it

WALMART GIFT CARD $100

winning bid-US $99.00

shipping-US $1.95
for a total of $100.95 for $100.00 gift card

$50 Walmart Gift card!

winning bid-US $46.25

shipping-US $5.00
for total out of pocket $51.25 for a $50.00 giftcard

There has to be something im missing because this doesn't make sense. LOL!!!