Also - not all turbos destroy tyres. The wear on mine is no worse than the wear off the road - so I'm happy to use normal tyres. Saves on an extra wheel, turbo tyre and faff.
I'm thinking not many people use £60 tubs - clearly thats a different case.
(and I reckon a good 80% of turbos never see enough use to cause any noticeable wear whatsoever !)