Be advised, mileage isn't all that important.
You can smoke a clutch in only 100 miles, if you abuse it, or have the clutch lever mis-adjusted..... or the user rides the clutch a lot.....etc..
That might be the case. Ever since I got the bike the clutch lever was adjusted too tightly, and unfortunately it took me longer than it should've to realize the problem, but who knows how many miles the bike did with the lever set up like that.
How do I know if the plates are too worn out? What's the recommended stack height for the plates?