A piece of software I sell is so complicated to set up/configure and missing any documentation so you have no chance to successfully use it without my guidance

A piece of software I sell is so complicated to set up/configure and missing any documentation so you have no chance to successfully use it without my guidance and support. The configuration is a one-time thing, the daily use is simple, so this is no problem for usability. And the software is a niche application with very few potential and real customers.