3.5 meter speed would work for some, but peoples reflexes vary too much. There will be younger guys complaining about the "slow" meter speed ruining their shots.
There will also be some of us older guys complaining that it's too fast. Someone in a forum once referred to us as having the reflexes of a hibernating bear. LOL
There are many ways to earn "free credits". And inexpensive balls from WGT available that can serve as an alternative to the higher level expensive balls. As the man said, "Choose. But choose wisely."
Phred952