I was wondering if you can buy planes with an iTunes card
Yes, you can. U can virtually buy any app or in-app-purchase with an iTunes Card :)
iTunes Gift Cards are loaded into your iTunes account, acting as “virtual money”. If you don’t have an alternate payment method (such as a credit card) hooked up to your account, the balance on the iTunes Gift Card is what you’re stuck with in terms of spending.
If you authenticate a credit card (or another payment method) to your iTunes account, any purchase will first take money from your existing balance that came from your iTunes Gift Card, then start pulling money from your alternate payment method. Probably TMI for this case but I’m just putting it out there :)
Yes you can it’s the method i use.
Personally I find it a lot more secure than hooking up your bank account to iTunes.