It looks as if the 5850 was so successful that ATI has decided to raise the price due to demand and poor 40nm fabrication results.
http://www.xbitlabs.com/news/video/display/20091102102459_Price_War_Reversed_ATI_Icreases_Pricing_of_New_High_End_Graphics_Card.html
This other article by Xbit may have something to do with it also.
http://www.xbitlabs.com/articles/video/display/radeon-hd5850.html
http://www.xbitlabs.com/news/video/display/20091102102459_Price_War_Reversed_ATI_Icreases_Pricing_of_New_High_End_Graphics_Card.html
This other article by Xbit may have something to do with it also.
http://www.xbitlabs.com/articles/video/display/radeon-hd5850.html