To give another perspective. Since he lives his day to day rather frugally, even though price doesn't matter in this instance. Would he perhaps have buyers remorse when spending possibly $70,000 more on a 458 compared to a Turbo S which is actually faster, even if the older styling.
One thing I've learned with high end stereos is that everyone has different tastes. He has to test them out thoroughly himself in order to know which he truly wants. Personally if I had the money, I would pick the 911 before the 458 if I lived modestly.