Old Pa's message really strikes to the heart of this Christmas exchange. I believe the first ever exchange was spearheaded by moogoesthecow but he left Head-fi quite a number of years ago so I took up the reigns because I really wanted this tradition to continue. I've been doing it for 4 years now I think maybe 5 and it has been wonderful every year.
That said, there have been hiccups. One year, I didn't get my gift, because the person I was paired up with (I get my wife or son to choose randomly out of a hat) decided not to send me something. He was too immature and spineless to step up and tell me flat out he was just going to leech my gift and not exchange. This is the worst case scenerio. It has not just happened to me but to a 1 or 2 members each year. Seriously, if you are in you are in, don't screw your partner.
Last year, I ordered a bunch of stuff for two head-fiers from a very well known audio store and even though online the indication was that everything was in stock, by the time the shipment was ready to go, stuff wasn't available, so these guys had to wait some extra time to get their complete gift. Waiting past Christmas is likely the third worst case scenerio. So, once you know your partner, shop and shop fast, get it out the door, and try to make sure the disc is in stock and get confirmation of that, I know I will be doing that this year. Amazon may well be the best place to go, though don't forget sweet spots like our Todd Green from Todd The Vinyl Junkie.
The second worst case scenerio is what Old Pa outlined, some guy offloading some dog of a disc and then hoping for some mint of a gift.
Come on now, if one wants to participate, then participate, no half-assed giving.
Again, if both partners agree to exchange used or new and used, or LP's or SACDs, or something else, more power to you, but the expectation should be that you will be buying 1 new disc. This is the minimum expectation joining up. Yes you may well be sending a choice used disc or a few or something entirely different, but again this will be the exception not the rule.
Please remember this is the season of giving not the season to be receiving...despite what corporately influenced western society is filling our heads with.
If this is not something you personally want to take part in, then please back out now.