Nowadays, most do not need to pay for an antivirus subscription. It just simply isn't needed anymore. I can't think of any oveerwhelming reason why you should switch Avast for MSE when the license runs out. It is your decision completely on whichever you prefer, and I am sure by that time you will have gotten used to Avast.
I think SAS is a bit overkill also, as well as the paid for malwarebytes. IF I were you, I would research how to practice 'safe internet browsing and surfing', while having an antivirus like MSE or Avast handy with the free version of Malwarebytes for a monthly extra scan.
This is just my opinion. At the end of the day, you are the master of your system, and you will be the one deciding the best security for your system based on many other people's advice. We won't be offended if you do not choose our 'answer'