What do you shoot now and what style of 9mm are you planning on competing with?
I have a few handguns, however, I wanted to step up and get really good with 1911 .45 and then maybe compete in the stock class.
So I picked a nicely tuned up GSG 1911 .22 to work on the basics and hell it's just a hoot to shoot. I can blow off 300 rounds in short order with breaking the bank.
Then when I shoot the S&W 1911 in .45 I find I am more comfortable with the size and weight and waste less of the $$$ .45s on the basics.
My brother has a 9mm Sig P226 w/.22LR Conversion Kit and he does much the same thing with the Sig P226 frame.
Most people in the sport will tell you it takes around 1000 rounds with the pistol before you start to get your group within the size of the palm of your hand.
If you have the $$$ to do this all with 9mm then more power to you, the .22 LR alternatives is something that works well for the rest of us.
And as shooting is a perishable skill, the more you shoot and the more often you shoot well the better.
I was always told that practice does not make perfect, perfect practice makes perfect so spending quality time on the basics is never a waste of time.
Just food for thought, your mileage will likely vary
Rick