The cost of a 30-second ad in the final episode of the series is coming in around a whopping $900,000, according to media buyers. Buyers suggest ABC has been seeking between $850,000 and $950,000 for an ad berth. ABC executives declined to comment. During last year's upfront, a 30-second spot for "Lost" was selling for an average of $213,563, according to Advertising Age's annual survey of ad costs in prime-time broadcast shows. At $900,000 a spot, ABC is clearing a markup north of 400% from advertisers who didn't reserve their time in the show last year.What does that work out to...about $30,000 a second? The 3 hour long May 23 event includes an hour long "recap" show, followed by the two hour finale itself - an installment simply entitled "The End." For those who are as rotten with dates as I am, note that May 23 is actually a SUNDAY (the show's currently airing on Tuesdays).