I went through a similar question in late may, where my K10D shutter started acting up and dragging the trailing curtain. shots over 1/500 started having progressively larger blacked out areas.
I opted to get it fixed, $325 CDN for replacement of the shutter, plus lens mount mirror etc.
camera came back fully cleaned (usually about $75 for this alone) and is like a new camera. It only took 10 calender days which included 2 weekends and a national holiday.
But, I also used this as an excuse to get a K7
the K10D already had a split image, and is now my MF body, the K7 is AF, and the *istD is an all around back up, plus the main body for MF FLash shots (using K mounts because it can run in TTL mode)