Guess I might count as two copies.
I bought the game during the E3 sale for $35 IIRC, then a couple weeks later the Blizzard expansion was on sale for $8, down from $20. But now during the Ultimate Game Sale the entire collection is $37 so I thought, what the hell, and contacted MS support to ask for a refund. I've already got over 20 hours in the game so I wasn't expecting a refund but low and behold they refunded not only the game purchase but the expansion as well. So now I own the entire thing. Easily the most pleasant support experience I have ever had. Well, Nintendo's always great as well.