MS Security/Windows Defender is free, unless you count whatever percentage of my laptop's purchase price was for Defender. Defender works fine and is very effective, plus it integrates very well with Edge, the Windows Firewall, my MS account and other aspects of Windows too. I augment Defender with my MBAM Premium Lifetime License. I think I paid $30.00 for it in 2012 or 2013. Between Defender, MBAM and using the brain I was born with I don't see a need to pay anything for online security.
C.H.