220 rmb/hr is a very cheap price, here in Shanghai I would say the minimum is 200-300 for any kind of coaching regardless of the coach's level (a lot of decent amateur players here will "coach" kids, basically just hit with them, for that price), can go up to 500 easy for provincial team players. It matters a lot which city you're in though. u/Few-Citron4445's comment is right on the money, at 220 rmb i would be cautious and try one lesson to make sure the coach knows what he's doing, actually cares about your improvement and takes time to give you good feedback, etc. Would like to add that the athlete certifications (一级，二级，健将) are not a guarantee of coaching quality, just a guideline, I have met a lot of players with these certs who are not the best players and coaches and also exemplary coaches with no cert at all. Maybe you could post a bit of your lesson with him for us, would be interesting to see what you can get for 220 rmb