This has nothing to do with money but with experience and knowledge. You can make stupid mistakes with a million dollars boat or with a 30 000 dollars boat. Today chartplotters are not expensive and all that navigate for a significant time have them.
Regarding knowledge in what regards navigation you can learn it by yourself but the learning is much slower and incomplete than if you do it on a formal way with a teacher that is a professional Captain that has many years of experience. That Captain had also formal teaching and he had benefited from all knowledge that had been recovered from the experience of thousands of experienced sea Captains. Of course, experience on the sea is also necessary but having a formal good preparation is a big help.
What take five said to professional sailors apply also to pleasure Captains:
I can only relate what I've seen in the fields of first responder, construction, and teaching. Getting the certificate proves only one thing: that you've been presented with information and have passed some sort of test(s). From many examples, I say that these courses of study do NOT have a direct correlation to ability in the real world. This is true in any of these fields and, I suspect, ALL fields. The real test is in the actual work situation. If anything, these "qualification" procedures are often very misleading and downright dangerous in some cases (as when applied to doctors, first responders, etc.) Not only that but they often become politicized, watered down by academics, unions, lawyers, etc, until they have NO connection with anything actually useful. Maybe they serve to filter out some of those who have made a mistake in choosing a field of endeavor, but not many. I'm not going to go into anecdotes but I have many.
After presentation of the information and whatever testing, RETENTION of useful knowledge is largely absent except on a very shallow level. Retention only comes from repeated, real-life usage: experience. The experience needs to be under the long-term tutelage of people with experience-on the job. These people usually do not want to be teachers because they can actually do the job. We used to have apprentice programs but academic bullies have all but eliminated them. The ones that still exist often stagnate and become ineffective because not much formal attention is given to them.
I will concede that the knowledge and information aspect of performing a job is, in the first place, essential but jumping through a maze of hoops is not necessary to acquire basic factual information. If you can read, you can learn the basic info. "Certification" programs, not all of them, often are expedited or lose sight of what is actually important. Schools that essentially print degrees on demand for anyone who can spell their name are becoming commonplace.