I totally understand the higher price for commercial use, here, it is cheap compared to the costs of hiring a designer, and it may have a real impact on your sales and ultimately earn you money.
But why is the price for personal use around $60? Is it some kind of a sweet spot because most people won't buy fonts anyways, even for $1, but those who do expect to pay that kind of money. Does it account for piracy, which I guess is easy and goes unnoticed if you only use it personally?