Amazon Prime is a great deal in the eyes of many Amazon customers, offering free two-day shipping for $79/year, among other benefits. But the price of Prime hasn’t kept pace with the company’s shipping costs, Amazon CFO Tom Szkutak said on the company’s last earnings call that Amazon is planning on raising the price of an Amazon Prime annual subscription by $20 or $40. Considering that Amazon has more than 20 million Prime subscribers, that could translate to a whole lot of cash.