Hot Shoe Repair for a 1d Mark II

I'm pretty sure my hot shoe / flash-sync contacts went south.
My 580ex II won't fire anymore on my 1d Mark II. Of course I
find this out in the field, where it worked fine a week earlier.

I've tried my flash on my 1ds Mark II and that works. So I know
it isn't the flash.

I've tried cleaning the contacts. Unless someone has any other
ideas to try, any idea what kind of cost I might be looking at to
get this repaired?

Thanks
Doug