How much one should spend at most for lessons compared to the buy-in he plays?

f.e 10BI/hour etc.

Of course it's not easy to find the perfect number but everyone understands that someone that plays on 2$ tourneys would just wasting money having a 500$/hour coach.

On average, 2-3x your buyin is probably around the max I'd suggest for most situations I've come across.

The first time I received coaching it cost about $75hr and I was playing $55 and $110 HUSNGs.

Due to the different game types, bankroll strategies, winrates, volume and goals, this can vary quite a bit though.

For example, if I was going to jump into PLO right now, I might only start at .50-1, but if I were planning to play 30+ hrs a week with a solid bankroll, I might be willing to pay $200-400hr for coaching for the right coach.

you are right obviously that when you are still in the micros it's hard to find a 2-3BI/hour coach. I play at 1,5-3,3 sng and i don't think there is a 9$ coach somewhere

i'm still not sure how much should i spend on a coach though. I play 300-400 tourneys per month and most coahes are in the 50-100 range. Still not sure if i'm paying a lot

I think training site content has really filled the desire for $1-5 buyin level players and their desire for faster improvement to go along with their regular playing progression.

Not that you can't buy a coach if you play the $2, but if we had overall data on how many people at the $2 level that have spend $100hr on coaching have progressed far enough to justify that investment, I think the answer would be quite clear.

And that's no knock on coaches, it's just that the average $2 level player is going to find something else to do, quit, fail, etc. in some way and not make it to the $50+ levels ever (some do of course, but I doubt it is even 1 in 10).