Well, the price must go up by $20 and when the time for renewal comes, Amazon will remind you that as of today it will cost $99 instead of $79 to keep your Prime membership.
Amazon claims that fuel prices as well as the cost of transportation have increased in these nine years and it claims that the price hike is the result of its own success. The number Prime items eligible for unlimited free two-day shipping grew from 1 million at launch to 20 million today.
Amazon does remind you that in return for your continuation of Prime membership you will get access to 40,000 movies and TV episodes, as well as 500,000 books you can borrow from Kindle owner's lending library. Amazon didn’t bother changing the price at its Prime website, as the free trial website we just visited claims that " After your free trial, Amazon Prime is just $79/year. You can cancel anytime."
If you act quickly you can still get the Prime membership for $79, but it will be $99 from now on.