Just for interest, I'm just about to replace two tyres on my 92' 110 200 TDi CSW, and though some figures might interest people.
We run on Michelin 4x4 7.50 x 16 XZL's, would admit that 98% of time is on road, (wife likes the look of the chunky tyres hence keeping them), the current front pair about to be replaced have now done 40,000 miles which is a distance I think is not bad for tyres.
In that time I've only had one incident where I've felt that they weren't giving me the traction I'd like, and that was wet road, left bend over a brow of a hill, when the weight unloaded from the back wheel on braking sharply the back twitched slightly, but we sopped no problem, apart from that they've been rock solid.
So are I've replace four of them and each time I've been able to get them for around £100 each inc. fitting.
Ta
John