Amazon announced on Friday that it has increased the price of its Amazon Prime membership--but just for those customers who opt to pay for it every month. While yearly membership will stay at $99 (or $49 for students), monthly membership will increase from $10.99 to $12.99 a month. That's an overall increase of $24 for a grand total of $156 per year. (Monthly student pricing will go up from $5.49 to $6.49 a month.) In other words, Amazon really wants you to just bite the bullet and spring for the yearly membership already.