Depends on your background. I suspect with an FAA ATPL the CAA will laugh loudly in your general direction- sorry about that.
My background- PPL/IR, degree in Meterology/Climatology, JAA Air Traffic Controller's licence exams passed (average >90%). You'd think they could at least exempt me an approved course: did they f***. I even had to take the comms exams. I object more to the fact that I had to pay £104 for the priveledge of being theoretically examined on how pilots should talk to Air Traffic Controllers when not 12 months ago I was on the other end of the microphone correcting pilots on *THEIR* RT!!!!
Also think about when you last had the occasion to sit down and study for any considerable period. I'm lucky- I went straight from uni to ATC training. That's a fairly hard graft. So when I came to do the ATPL exams sitting down studying is nothing new.
That being said, there is nothing to stop you doing a distance learning course at a knock down price. However, even considering my advantage in the groundschool I am still doing a residential course (at BCFT), and I can honestly say that it really is worth it. What you gain from the instructors in the classroom being able to impart knowledge directly to you will more or less ensure you get all 14 straight off. Particularly in subjects like PoF, where the questions are really, really abstract. You can have a degree in Aero Eng and still struggle with the PoF exam.