Last summer my strap came off my D3 and the camera fell to a wood floor from about 4ft height. Bent the hotshoe. With channel locks and a screwdriver, I got the shoe working again, able to fit a flash and it still fires.
I once dropped a Canon 70-200 f/4 L lens out of my bag when getting out of a car. Front element had a big scallop taken out of it and it wouldn't focus at all. The repair was less than $200 so it wasn't that costly, just high on the pucker factor.
Really, the most expensive blunder was walking on a jetty in the Bay of Cadiz, Spain and stepping on a rock which wasn't stable. The rock rolled and I stepped straight down into the bay, just over head deep with my Leica M4 and 28mm Kobalux lens on my shoulder.
I took the camera apart immediately and tried to dry it but the damage had been done from the salt water and it locked up shortly thereafter.
Sherry K repaired that camera and it cost almost as much as I paid for it. I still have it to this day and it works perfectly.
Phil Forrest