Clutch?

This is pretty simple: How long did yours last? My car has ~174k on it with the origonal clutch. My rear main seal has developed a nasty leak, so it along with the clutch will be replaced this weekend. Me and my dad plan on spending most our Sunday doing this. My clutch still works great and has a lot of clamping force. Only sometimes when I run it rough does it slip a little. I think it could have his 200k if it wasn't for the leak. My car has mostly highway mileage before me. Just wondering if that kind of wear is normal. I read somewhere that they should only last 28k. My dad says he charges $1000 for a clutch on a quattro, mostly labor, I would be pissed if I had to pay that every 28k...