Whoops! ICANN haven't altered their price controls for .com recently. Might be getting mixed up with the .org kerfuffle.
In the current .com contract, prices were fixed at $7.85 until 30th November 2018, and are allowed to raise the cost by 7% per year after that, under certain conditions:
"7.3(d)(ii) Registry Operator shall be entitled to increase the Maximum Price during the term of the Agreement due to the imposition of any new Consensus Policy or documented extraordinary expense resulting from an attack or threat of attack on the Security or Stability of the DNS, not to exceed the smaller of the preceding year's Maximum Price or the highest price charged during the preceding year, multiplied by 1.07."
