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I have a grip. I do not want to take all photos in portrait orientation or jack my wrists around just to take a shot.
If the repair is expensive I will simply buy a new camera.
Just a shot in the dark here, but I have had my 20D with Batter Grip act up before, would not fire, then would take a few, then not again. It actually happened to me yesterday and the problem was a very simple fix. My battery grip had become slightly loose causing a faulty connection with the camera. It wasn't loose enough to completely shut off the camera but it did affect the shutter.
I tightened the little wheel and everything was better, fired another 200 shots without incident.
I'm sure you probably did this already, but if not give it a try, might save you some money.