Ive just bought a B6 1.8T Cab coming from a B5 myself love it (B5 more though thats my proper toy when its done haha)
Problem you face is wether its been run into the ground and you end up having to fork out for control arms, suspension components wheel bearings, timing belt change etc etc engine wise its probably got another 50k in it personally id hold out and find something around the 150k mark thats got a bit of history of work/servicing with it.