I wanted to purchase a used iPhone. What level of the battery would be reasonable and below what percentage I shouldn't buy one?

I'm switching from an Android phone to an iPhone for the first time, and I play games a lot. Any advice before purchasing one?

I'm switching to Apple from Android. I can afford an iPhone 14 Plus, but I don't like that it operates at 60 Hz because I play a lot of mobile games. My other choice is a previously owned iPhone 13 Pro Max with battery life between 90 and 98, but which one should I choose?

Which iPhone should I purchase? I can afford an iPhone 14 Plus, however it runs at 60 Hz, which is a drawback for me because I play mobile games a lot.