Guys
look into Yinhe Y40+ balls. Its very similar to Nittaku Premium and at a much better costs.
Back to OP question
I have so many sample balls, I am like an Ball Junkie.
For a year or so, I did need to factor in "budget increase" on training balls.
But now I'm getting my balls straight from the factory (with my own logo/brand), so its all fine.
For 3 star, I prefer the seamless balls over the seam balls, however Nittaku Premium is always the number 1 in quality and durability, but since SA market isn't right for "double the cost" balls, I don't bring them in anymore.
Yinhe Y40+ is a very good substitute, and currently my samples are still looking great (I receive it straight from the factory - it was 2 weeks old when I received it)
It was bulk manufactured in March, so I think many sellers won't have stock yet.
Most of my clients are struggling with the costs of balls.
One coach for example used to by 144 gross bags x 10 a year.
now he hardly buys box of 72 x 5 a year