Buying all Xbox and Amazon giftcards

Hello, I have a good amount of cash to buy some gift cards for some stores. I'm mostly looking for gift cards that are from Xbox, PlayStation, Amazon, or GameStop. These are the money that I'm willing to spend

$15 gift card/ I will pay $10 for it through PayPal
$20 gift card/ I will pay $15 for it though PayPal
$50 gift card/ I will pay $40 for it through PayPal

My kik is alertgame