Actually, $59.99 isn't the publisher's price tag. You can see that when a game is offered at $59.99 in one retailer and $54.99 in another.
The retail price tag is a sum of: Publisher's price tag ($30-$40, that's the price retailers buy a game for) + what the retailer needs to earn to cover all costs).
So actually it's the market who defines the tag and adjusts it when retailers offer different prices.
That's why many people often find digital games price tags too high. Actually, a publisher earns almost 100% of $59.99 when offering a game digitally, because he can massively reduce costs for shipping it.