I agree with the main point Matt has said. But, IF and that's the key, if you feel you have improved, by seasons end, there should be many used balls for sale by those who want the "newest and greatest" balls out. Again, IF, you feel you are ready to take a step up in balls, that's a good time to buy a ball or two, stepping up a bit, and during the summer learn with those "mid-range" balls.
There's nothing wrong at all about getting a used ball, having it plugged and redrilled for you and the improvement, we all hope, that you have made. If you don't feel you are ready for the next step up, nothing wrong at all, just get comfortable with your style or if you want to improve on spares, then work on that before stepping up in balls.
If you ask many folks, most will tell you that spares kill most folks scores. One day you can't miss, then next you couldn't hit the side of a barn. Consistently, that's the main key to anything you do. Be it bowling, golf, basketball, you name it, that's the key.
Feel confident, comfortable and know that one part of the game can ruin the rest. I've always said, get consistent with spares before going to the "big hook" game. IMO, you'll be better off.
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az guy aka: R & L Bowlers Pro
rlbowlerspro@cox.net
www.rlbowlerspro.com