I was with a company about 5-6 years ago that took on C4 for the lower end jobs.  Their products had so many issues (that C4 admitted to at the time so don't get your undies in a bunch) so we dropped them after less than 2 years.  We could no longer support the 60+ clients that we had done work for because we no longer had access to the software.  We had to refer our clients to other C4 dealers or directly to C4 themselves.

I get this is how they do it but I will never support a company that operates like this.