Pricing error on the HD 4870 X2...

Big thanks go to David E. who pointed out that we used the total pricing of the HD 4870 X2 on our Reactor configuration page, when we should have been using the price difference between it and the default HD 4870 ($560 vs. $250.) The prices have been corrected, so it now costs a much more reasonable $250 extra to order a Reactor with a single HD 4870 X2, and $810 extra (total) for a pair of them. Sorry for the confusion!