We don't know, maybe their tennis expense is less than 1% of annual income or a much smaller percentage of net worth. Meanwhile, it wouldn't surprise me if lots of parents right here on this Board are paying upwards of 5-10% of annual income on their kids' tennis.
Looking at nominal amounts rather than percentages in any business or family isn't the best way to take risk or maximize material enjoyment/the return on investment.
Sorry, I'm not saying it literally, but meaning that you can't just buy a tennis player. I'm just assuming they are doing it to make him a pro as per the post about that kid. Hey if parents want and can afford to fork out wads of cash keep it coming, but doesn't guarantee a tour player, which I suspect many of the parents are looking for.
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