I've heard nothing but bad things about buy.com in the past few years. I use to buy from them ages ago but then the prices on products stopped being as attractive. I think the climbing puzzle aspect of this game will get boring rather quickly.
The problem with waiting is that some of these niche japanese games never drop in price. I have some backlog at the moment, but I'll still jump on a good deal on this, because a price drop may not come for a while.
I wonder how many purchases they've lost on this. I went with Buy.com and I bet a lot of others did too once it became clear Amazon was not going to match it. I know buy.com is not a threat to the level of Best Buy or Kmart or anything, but people will go where it's cheaper.