I know its a different cat, but I have a Yamaha 2 stroke and no one here in bismarck carries their oil at a resonable price any more. I ended up finding a Yamaha rebuilding company called Hydrotec Marine and they shipped it to me for cheaper than I could get it anywhere.
You might also want to look at the Amsoil HP Marine. Check out their website, their oil is supposed to be compliant with the XD-100.