Buying Costco gift cards on eBay for a discount

I'm constantly looking on eBay for certain gift cards to get a discount in essence at the store. We've received 10-20% by buying gift cards for Marshalls, Lettuce Entertain You restaurants, etc. Some stores go pretty close to face value, while others get a bigger discount b/c they may be more obscure or not as popular. For example, Walmart and Target gift cards almost always go for 98-99% of what they are worth since almost anyone/everyone can get something of use at those stores. For others like say Club Monaco, you may be able to get 25-30% off b/c they're aren't as many Club Monaco stores and/or it doesn't fit everyone's style.

Anyways, Costco gift cards fit the 98-99% of face value, since most people can get something there. In fact, some gift cards go for more than the face value sometimes, b/c non-members can use the gift card to buy something at Costco even though they are not members.

There is a cashback program at live.com. It's been well documented at Fatwallet, and other deal sites, where one can get 25-30% off of a Buy-it-now eBay auction. So what's been popping up on eBay are gift card auctions with a Buy-it-now price of something higher than what the gift card is worth.

For example:
$500 Costco gift card listed at $570 Buy-It-Now
Buyer pays $570, but with 25% cashback (on $570), only pays $427.50 for the $500 gift card
Seller gets $570, pays approximately $54 in eBay and Paypal fees, profits $16 on the sale.

I've bought 2 gift cards now using this method, a $100 Costco gift card for $91 after 30% cashback, and a $100 Bed Bath and Beyond gift card for $75 after 25% cashback. The cashback is not payable for 60 days, but I have received confirmation that it's there. I've also put up an auction of my own on eBay selling a $500 Costco gift card, just to give it a try.

So go out there, check things out, and save some $$$!!! You can even buy my Costco gift card and get your cashback/discount that way! I'll show you how to do it, if you want. Just drop me a line.