I can pipe up as a retired specialist in "distance delivery" or "distance education programs" as they call this one. I took a pretty close look at the site from the purely academic standpoint.
Distance education (the new buzzword for "correspondence classes") depends a whole bunch on student motivation for success. This one seems well set up for feedback, but as with all of them it's only going to be successful if the student keeps his head down and his butt up at the work table. The instructor can help motivate, but he's not on hand to kick a$$ and take names if a student doesn't follow through. That's up to the student.
Cost compared to time and content seems competitive with other correspondence programs of similar duration and depth. Frankly it's even a little low when measured on that scale.
Lot's of intro material that some may feel is too basic, but is necessary for the average new student.
Up to the student to decide if the content (especially final outcome) meets his needs and interests. It's an indicator of emphasis that course fees include a BP revolver kit rather than a basic rifle kit. I'd be pretty sure that it met my needs if I was a revolver enthusiast, but a little hesitant if my interest was only long guns. Research and questions would be required.
I'd treat this like I do any expensive service, whether a guided hunt or roof repair on my house. I'd ask for the email address and phone # of past clients so I could contact them directly with my questions.