Technofreak: I can't agree entirely with what you say. Yes, soft V hard compounds is one important factor. I get around 50k out of my tyres and they're excellent in the wet. If I was only getting 35k I'd be pretty disappointed.
It's not all about soft and hard compounds, tread design has a lot to do with how well a tyre grips in the wet,
+1
The last set of Bridgestone 4x4 tyres I had lasted about 80,000km and there was nothing wrong with the grip right up until we decided to replace them because a couple were getting borderline for a WOF. Mind you, with a 4x4, I wasn't driving like some boy racer out to show how fast I could go around corners. No doubt driving style is a big factor in how long tyres last.
I certainly agree with the comments about not skimping on tyres. Buying a good set of new tyres before the old ones are completely worn out is money well spent so far as I'm concerned.