UKPassats

My clutch has recently started to slip. Although not very often, it first happened a couple of months ago as I was accelerating on to a motorway from a slip road. I was in 4th and give it a bit more whellie before changing to 5th. I then had that horrible slippery feeling as the revs shot up without the pull. I panicked, called my vw machanic/doctor who said bring it to him. He couldn't get it to slip and said the clutch seemed fine. He mentioned something a long the lines of the flywheel sticking I think. But said not to worry. So after that nothing until a 200mile round trip 2 days ago. When it did it twice in 5th gear whilst accelerating again on the motorway doing 70ish.
So do I bite the bullet, or live with it for now?