The dealer cost for the X3 on the BMW 2 year/50,000 Extended Warranty is $2000 and the suggested retail is $2750 according to this document -
http://www.bmwmotorsports.org/pdf/B0...ranty+Plan.pdf Although this document is about a year and a half old, I doubt that the price has gone up that much - so it sounds like the salesman is setting himself up for a nice big commission check. Are you dealing with Dave Walters BMW in Akron?
Another thing to ask is if the warranty is transferable. If so, it could make the vehicle more marketable if it has an extended BMW warranty, versus a Toyota warranty.
While your dealer may do both BMW's and Toyota's, if you are ever anywhere else in the U.S. and have a problem, it may be easier to get the problem address if you have a BMW warranty on a BMW.
Finally, unless you have the ability to still negotiate this into the deal, it may not be a good idea to pay for something that you won't even be able to take advantage of for many years down the road. You can always explore getting an extended warranty as you get closer to the expiration of your OEM factory warranty.