it is hard to make money at building non harley customs. Even the cafe style harley's are having a hard go of it. These days you can't ger anybody to pay more than $5000 for a complete japanese based cafe racer (with lots of custom work) and more than $15,000 for a comparable top line british bike (unless you are kenny dreer). If you were to charge the normal labor rate for a jap custom you are looking at a $10-15K motorcycle, same for a birt bike going up to $20K.
Parts are about the only thing that seems to be making any profit, because you don't have the labor invested like an individual bike. Plus the guys that are into this kind of bike are low budget types, so they would rather spend the time on their bike and the money on a high quality piece. Airtech, raask, tarozzi, and evan wilcox all seem to be doing ok off of just parts, meanwhile all the local shops who work on these bikes are beating their brains in to keep up on the shop rent and usually relying on another business to prop them up.