I have some rust (about 10cm long) where the rear bumper attachs next
to the rear wheel arch on the offside (right hand drive) underneath
the fuel filler cap - in fact where the bumper is attached is
completely rusted away so it isn't really attached and is just hanging
there... has been like this since I brought the car 18 months ago.

Anyone any ideas how much it would cost to get the rust chopped out
and a new bit of metal put in? Does it being near the fuel filler
hose mean that would have to come out for safety when welding,
increasing the price?

Other option is just leave it but the car is fine and only has 67000
miles on it...alternatively are there any cheap 'fixes'?

Cheers.