"With Good Antivirus that is free like Microsoft Security Essentials. Avast, and AVG" I can tell you, AVG and Avast are not good antiviruses, trust me.
Avira is the only free antivirus I would recommend, next to BitDefender Free Edition. If they believe their free antivirus is really protecting them, it is not likely they will switch to a paid one, you get what you paid for.
Safe Surfing and Browsing won't do anything, somebody who only goes on 4 sites can get a virus that they got from the internet!
Just remember this, safe browsing and not downloading does NOT mean you are virus free.
Some people want full protection so they will go for paid products such as: BitDefender, Kapersky, and ESET NOD32. Each antivirus has it's downside, no Operating System, no Antivirus, and no browser is perfect, just be smart on what you browse and download.
Yes, they are enough, but not AVG, that has loads of False Positives, don't use it. Avast, is, kinda good, but I wouldn't recommend it.