@Glasscocked - that sucks that it took them that long. Yeah, that'd annoy me, too, even with the 100% trade in.
@jam86 - the way you worded the last sentence of that is a little confusing. I would expect anything dealing with Black Friday to be out of their price matching policy. I think they'd deny you the reverse price match unless you put up a fuss and got manager approval. I would likely try to put up that fuss because I know it'd be a really busy day for them and there's a chance they'd just say "screw it" and do it for me because they've got more important things to worry about than a $30 discount on a game that he knows they're eventually going to sell for $30 anyhow.
Now, it is a bigger pain to do a return/re-buy, but there is obvious value in doing it that way, if you can. If you return/re-buy, then you reset the clock in case the game price drops even lower within the next 30/60 days since it'd be a new transaction. While Halo 4 may not go even lower that soon, other titles, like, say Lollipop Chainsaw, probably would. It came out at $60 in June or so right? Then at least by July/August I'm pretty sure they had it for $40 at some point, falling within the 60 day return policy. So if you just did the reverse PM, you'd be stuck at the $40 price point because your 60 days on the purchase would pass. If you did the return/re-buy say in August for $40, then they drop it again to $20 by September/October, you could return/re-buy again and get it for $20.
And yeah, it's going to be really annoying if they try sticking to that "showroom items only" crap. Stupid strategy on their part, too. Too many exceptions on deals just causes confusion and anger for customers and will just drive them away. If I keep getting problems every time I try PMing Amazon or someone for a video game, I'll eventually get fed up enough to quit doing anything with Best Buy. If they actually "play ball" with me, then I'll keep shopping there. Simple as that.