geniune reason for sale.. need a new camera lens for work, so will happily swap the entire job-lot for a Canon 400mm f2.8 lens in very good condition.
Jesus camera lenses are expensive I didn't know that.... sorry to clutter your thread good luck with the sale

.
haha hedgy, yes they are, and its painful when they no longer work!!!
as to the lens you have ..don't they have professional services to repair such expensive camera lenses?
hell do a web search of pawn shops worldwide you may get lucky......(just saying) lots of stupid stuff like that comes in when people divorce/die or whatever
find a broken one ..contact your local univ see if you can use a 'clean room' pay some engineering student in pizza beer hack a new one together see if
you get lucky...but any engineering school would prob have a 'clean room' for hd repair etc ..might not work but wtf
just saying