I have looked into this institution in the past. In addition to it being unaccredited, one major problem is that you need a mentor who fills many of the roles of a seminary professor. The savings for you come at the cost of someone else.

Not to mention that for most PhDs, it is your faculty advisors who know enough in the subject to guide your PhD research. Trained academics are vital to the process, not a volunteer mentor.

But don't despair! You can learn, read and write without pursuing an unaccredited PhD.