Just in case anyone was still reading this thread, it helped me a bunch. I was purchasing tickets that were $303 each. I bought $300 in gift cards. Then, I purchased a round trip ticket for $200 and a one way for $100. I cancelled those flights and then used the travel funds to buy the $303 ticket (plus $3 to the credit card). I did it for all three of us and and saved $87.75. I purchased the cards using my target visa and a pharmacy reward.
Just be careful if there is a minor in the group. You will want to book the adult, book the child, cancel the child and then cancel the adult.