After commanding a whopping $750,000 per spot during the upfront buying period last fall, Fox's American Idol has been recently commanding prices of $900,000 per spot, largely helped by the dearth of commercial availabilities on other new programs since the writers' strike began on November 2, Reuters observed Monday. The talent contest, which generated $810 million in revenue for Fox last year, is due to return to the air tonight ((Tuesday). Meanwhile it was reported that Sunday night's debut of Terminator: The Sarah Connor Chronicles produced the best ratings in three years for a new scripted series among 18-49-year-old viewers.