It's about an hours labour book time and the boot is about 30 quid from VW, non genuine ones about 10-15.
It can be a pain in the arse job. It's a pretty decent price from a garage, if it's a main dealer then very good. On the high side for an indy but hey ho. People have to make a living.
I wouldn't worry about it, if it's only for a few weeks.. put it out of your mind. Depending on how/where the boot is weeping from, if it's lost it's inner or outer clip (fairly common) then a cable tie will suffice. If it's got a massive gash or tear and it's pissing out grease then there's not much you can do, because you can't really stick anything to it, no matter how clean the boot may be, it moves and compresses far too much so anything you put over it.
Put it out of mind until it's done.