In buying a KTM obviously you aren't looking for the cheapest two wheeled transportation anyways, so I wouldn't sweat spending a few extra bucks on the oil. Motorex is manufactured in Switzerland and is the factory fill product on all KTM's and is developed with KTM engineers specifically for KTM bikes.
http://www.motorexusa.com/prod_detail.asp?id=137
For how often we have to change oil, spending an extra what $20-30 a year on oil is cheap insurance that you are protecting your motor.
