I do not disagree with you that if a Free one can do your job then why should one waste any money. And thats why I prefer Avast! as it provides a more comprehensive and complete protection than Avira Free.
I would have accepted this had it been a car but a AV. Otherwise, I do not subscribe to this type of beliefs which can not be analytically supported. Please do not misunderstand me, there is nothing personal against you in my above comment. I just prefer not to remain biased against or in favour of any idea.
As far as performance goes, I hope that you would agree that there is hardly any difference between the top rated AVs like Avira, Kaspersky or NOD32. But where NOD32 scores above others is that it uses least system resources in comparison with any other AVs.
Furthermore, IMHO, Retrospective / ProActive Test is more important to judge the performance. Please look at the number of false positives by Avira, it is "many" where as for NOD32 it is "none". Now when an AV flags so many false positives then the chances of catching increases substantially, but that is not a desireable way to perform. As in catching wrong doers, safe one also get lebelled.