Hmmm, I thought it was closer to 300.... But anyway the answer is yes. For any quality solid mount, that's the going rate. But hey you have a formerly 10000 buck PJ and you should have spent at least another 1500++++ on a quality screen (if you didn't then you should have bought a cheaper PJ). I surely hope you didn't break the bank to the extent that you can't afford an extra 2 to 3 hundred clams. The fact of the matter is PJ alignment is crucial, believe me I've had a PJ on a cheapy mount and it's a source of frustration because the thing will move. Having to move the PJ around to get it to shoot on the screen sucks. The InFocus piece is a very quality item. It has 2 struts, and is probably more stable than anything out there, other than something custom made by some serious metal fabricators. Don't forget, it's made by the manufacturer specifically for the unit. Unlike anything else available at any cost.
Regards,
Edward