I always recommend courses on Udemy, Coursera, etc. Anywhere you have to pay for the knowledge. The money seems to be an important filter for quality. Not always, and there are certainly exceptions, but in my experience, it's highly predictive of useful knowledge.
I don't think it is, because I'm talking about a marketplace where goods and services can be exchanged for a price as being a filter for quality; otherwise known as capitalism.
If you assume price=quality and therefore always buy the most expensive one, you’re not participating in price discovery and they can just raise it, producing Veblen goods.
Oh I think I wasn't clear earlier. I'm not actually arguing that the higher priced the good, the higher the quality, since luxury items are one obvious exception. I agree with you there. I was making a comparison between educational lessons that are priced for free (like say YouTube tutorials) versus anything priced above $0.
I think just having a price tag at all incentivizes a marketplace where the best lessons compete. Now how one determines that quality though...lots of different heuristics and I have a few thoughts on how it could be done better but reviews, especially negative ones do a fairly decent job of assessing for qualities.
My apologies if it was not clear what I meant earlier.
