I think they can only be bought at the white food/drink tents in the Studios. I bought mine at the Bloody Mary white tent. The 30 dollars off goes on your receipt, after they scan your AP. I had no issue paying the $120 for the $150 card. It comes with a red thin rope lanyard, but I refused the lanyard as it’s a credit card sized gift card, and I just rather have it in my purse.
I used it at Breadbox with no issue, and don’t forget to use your AP discount before paying for that food or drink, if you have the AP that has a discount. Though any kind of AP does get that 30 dollar discount though, with the scan of your AP at purchase of the card.
I was lucky, as I was only there the first day of the Mardi Gras celebration, on Saturday. We left Saturday night. Got the AP magnet at the 5 and Dime on my way out of the park. Joined my season passholder DD at IOA, as she was blocked out of the studios that day, due to concert that night. She got her AP magnet at the Toon town large store.