This is one of my pervious trade topic,

https://bitcointalk.org/index.php?topic=208091.0

I am not sure how to work with escrow in this case.

Edit:

I have added bitmit link with escrow enabled, head to that link if you still want to purchase.

https://www.bitmit.net/en/item/57936-hearthstone-beta-key

thanks.