"I wouldn't worry about it. Shutters can (and do) eventually fail, but the good news is that repair is relatively affordable. I know a few folks who have had shutters replaced, the cost has generally been between $200-300."

from some guy, here: http://photo.stackexchange.com/quest...a-dslr-shutter

And a Canon one: "Canon gave an original estimate of $220 to "check all functions and repair to good working order". They have since sent another, final estimate of $640 to "replace the shutter + mirror box"" from here: http://photo.net/canon-eos-digital-camera-forum/00WEtl

According to this, a non-Canon shop may be cheaper, at $160 ( see here: http://www.dpreview.com/forums/post/40829447 )

According to one source, inflation has kicked in: "Canon wanted to charge me $600.00 to replace my 5D shutter last month.Thats just ridiculous. Two years ago they did it for $250.00 and change.", from here: http://www.fredmiranda.com/forum/topic/1297688

In other words, no, I don't know. If you're trusting people on the web, the $300-$600 ballpark looks about right.