I believe that it would be a worthwhile profit making business for the makers of Transdem, that they offer two products:
1) Transdem program for $33 ???
2) A custom DEM creation person under the direction of Roland Ziegler, that makes DEM's for a small commision, of $5 for a small DEM, $20 for a large DEM, and the profits go to Roland Ziegler.
Some people lack the skills and patience, to master Transdem, and only want one particular DEM route ... although the learning curve of Transdem is not that hard to overcome.