Is that not a case of increased demand vs decreased supply? I read the old mkivsupra.net forum for years before I joined this new one in 2005 and hardly anyone had done the conversion on the old style forum, where's in 2008 it seems every bugger has done or is planning to do the conversion but 6-speeds are thin on the ground, so thin that I'd be looking to supraforums for the parts with so many 6 speeders swapping the TH400's and other drag racing boxes.
MVP sell brand new v160's for $5499 (shipping excluded) with a year warranty from Toyota.
I'm surprised non of the traders on either side of the pond sell transmission conversion kits, even if they don't include the box itself.