I will ask you to add a note saying "This Payment is for Dota2(STEAM) Virtual Goods that was transferred and received already. The goods doesn't have any Tracking/Shipping therefore it doesn't have any Proof of receipt. I agreed Not to "Chargeback/Dispute/File an Unauthorized Use" once this Payment was sent already.
10 Dota 2 Keys for sell for paypal
$2.4 each
Here are some rules so the trade go easily:
I have rep thread in dota2traders community.