The old damp boot problem - HOW MUCH?!?

Hi folks

This is my first posting on here, but having searched the forums I can't find a direct answer to my question.

I've had trouble with the boot of my 1.9TDI being a little on the soggy side before and eventually traced it to the washer hoze connector having popped off behind the nearside wheelarch, which, once found, was easy enough to rectify.

However the boot still seems to get damp on a regular basis and smells a bit fusty, but I can't see anywhere obvious that the water is coming in...

I've yet to re-check the boot seal, as I think that may be part of the problem and will add the requisite drain holes when I get a chance.

I also think that there's possibly some water coming in around the rear wiper mechanism, so need to investigate there further. When I lift the boot lid there are usually a few drops of water that drip from the bump-stops on either side, from inside of the lower tailgate edge.

Now, I don't think my washer hose is leaking and suspect the problem actually lies with the rubber bush/gasket/grommet where the wiper spindle comes through the glass.

I went to my local dealer last week to get a replacement for it and nearly died of shock when the parts assistant came back and told me that this single part was £76!!

Now I'm assuming that he must be mistaken, as it's a small bit of rubber (fnar fnar) that I'd expect to cost no more than a tenner at most! I'm wondering if he's quoted me the price for the whole wiper mechanism/repair kit?

Can anyone tell me the precise part-number for the part I require, and is it worth getting any other bits whilst I'm in that may help alleviate the leak?

Other than the above options, is there anything else that might cause the damp boot?

Thanks in advance, Rob