I think the best answer is to go to your pro shop and see what he has laying around that is cheap!
I guess this isn't good business practice, but I wouldn't sell you a new ball. I would make sure that you get as much fun out of "10 pins" bowling as you do your Wii.
You have your local pro shop guy plug something and drill it for next to nothing. That way you don't invest a crap load of loot for something that you might not like doing.
I'm sure this will garner a bunch of attention and many will disagree, but if I was your pro shop operator, I have a hoard of old used stuff laying around that I could give away just to get a guy started. At the most, you would pay for plug and grips (if you went that direction) just to cover the cost of material.
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