I did self study (many material and vids, FAA books etc.), bought the ASA test prep BOOK ($24??), used their prepware code to get sign off.
Total cost was the price of the test prep book.
I did this for PAR, IRA, and CAX. There is no reason for anyone to spend 16 weeks in a "ground school" and pay $400 IMO for private.
I also recommend taking the written early, its an easy test as long as you study, get it out the way.
good luck on your test
I admire your self discipline, and suspect you are maybe the exception to the rule.
I think in general, even if some folk genuinely have a burning passion to learn to fly, it can be hard to self-learn without some kind of pressure or tutelage. At least for me, there is a little extra pressure to keep going knowing there is CFI online "waiting" (even though of course, he or she is not actually waiting...you know what I mean) for your next quiz, to grade, correct, and instruct. It helps that you get actual feedback, can ask for more explanation or check with a human online when not sure if one understands thing correctly.
I really didn't have the self learn option, as I'm an American in Norway, no the exam so far at least, is in Norwegian. I've used some ASA books beside my Norwegian course, but still had to clarify a number of terms, etc. and the airspaces are slightly different, as well as regulations. I speak Norwegian fluently now, for a number of years but this is technical Norwegian and "legalease" Norwegian. Lots of new words for me to learn.
Also we here learn online, but also are required to go through twenty hours classroom course to review it all.
Also not sure how the exam, if at all, differ from the US (many Norwegians travel to the US or the UK to take ground and or flight school because it is cheaper, and they say, easier) but there is a LOT to learn.
Anyway, my situation is not the norm for most, but even so, for many folks it just is plain easier, and maybe better to have that online feedback (if not an actual classroom) to get better understanding. For some the math and trig does not come naturally, and here too it helps to have a CFI ready to jump in and point out where one is thinking wrongly, or missing a point.
I don't kno how it works in th US, but here you have a year to get through the course, and if you don't make it in that time, you pay extr to extend it another year. I know, it's a long time, but for myself (keeping in mind the Norwegian difficulties) it is taking a lot of my time to get through.
This forum is enormously helpful to me in a lot of cases, but even here one can get conflicting answers, and I sure need to be able to ask "my online CFI" (as well as my actual flying CFI) about some things.