Taking an old Vauxhall to a main agent ... that's one hell of a way to spend a lot of money.

Indeed!

The job will break down something like this:

Labour to remove the gearbox: £400

Release bearing: £10 - £50 (depending on if it's part of the slave or not)

Labour to change the Bearing: £50

So, you're up near £500 already. Now, the clutch has done 80k, and you've knackered the release bearing. This is either a lot of gear changes, or a lot of sitting with it in gear with your foot on the clutch. There's a good chance the clutch itself is worn. Changing it will add only another £50 labour, but will add £300 - £500 for the parts for the clutch and flywheel. If it is not changed, and then fails in the near future, then you are looking at forking out the £400 again.

So, you've got 3 choices:

1. Replace the lot at £800 and get another 80-100k out of it

2. Spend the £25 to remove the clutch whilst the box is out and check the state of the linings and the DMF, being ready to put a new clutch in if either is worn out.

3. Save the £400 for the new clutch and take a punt on it being OK for a while yet, but expecting a repeat experience in a few years when the lining or DMF does wear out.

We had a release bearing failure on our C4 Picasso at 90k. New clutch was about £800 all in. In fact, when inspected the linings were only half worn, and there were no real signs of DMF distress. If I had been DIYing, I might have elected just to fit the £10 release bearing and live with the fact I might have to have the box out again.

To prolong the life of the release bearing, don't sit with your foot on the clutch, and to prolong the life of the linings and DMF don't overheat the clutch - no holding it on hills, or excessive slip when pulling away.