Ammo dealers and mfrs will hate me for this.
IMO, a better way to practice costs nothing. Shoot .22 if you want, but it will probably not make you a better shooter. Use a .22 to plink or introduce somebody to the sport, but for serious practice....naaaah!
Dryfire, dryfire and dryfire your 9mm pistol some more. Serious shooters will benefit more from dryfiring, drawing and dryfiring, than shooting .22
But that's just me (a perhaps a few others in this forum).
Depends what you want to accomplish in your shooting career.
Even at the range, dry fire a hundred times before your first live shot. Takes discipline, but this technique works. Will save you money and get your where you want to be sooner.