I have managed 30k out of a set of Nokian Wr g2's.
I got them for £60 a corner 18 months ago so they haven't done too bad. Cold weather tyres aren't meant to kept for more than two years.
They are almost on their limits, and I have just bought a set of WR D3's tonight for £70 each.
If they are as good as the current set and last as long I'll be a happy bunny and won't mind the slight increase.