I am planning on a new build very soon and I'm looking to do top tier gaming with it almost exclusively. My original plan was to order it with one 5870 and add another 5870 along the line (with the impression the 5870 was the best price point for a high end card and that it scales well with crossfire). However I've ran into a few comments that crossfire "isn't worth it" for one monitor. Would I be better off saving for a 5970 or is Crossfire fine for a one monitor setup? I'm going for a budget of around $2000.
Also, is the i7 900 series worth it if I'm not going triple crossfire?
Crossfire is fine for a single monitor and getting a second one later down the road is a cheap upgrade option to greatly improve your gaming potential. No reason crossfire wouldnt be worth it on a single monitor.