Where to buy $5 itunes gift cards?

Please forgive me if it's not the right board to ask this question...

But I have a need to buy some $5 itunes gift cards and I just found out the minimum denomination of itunes gift card sold on apple store is $15 which doesn't suit my need.

Is anyone here knows how/where to buy $5 itunes cards? I did some google search before and looks like some websites give $5 cards for promotion purpose. So there must be a way to get it I guess. Otherwise how did these websites get it?

Any comment is appreciated!

Happy holidays!

Thanks!

So looks like there's no direct way to purchase $5 cards? $10 is still too much for me, because somehow I need to buy a lot... 😱