Personally as an Avast Free(loader) user, were I to purchase I certainly wouldn't use the auto renewal/payment as the charge is 100%.
There used to be a renewal discount some time ago, now it seems to be an offer on first purchase then 100% on renewal. Frequently there were discount offers from within the User Interface to renew for those not on auto renewal.
This is also an issue with consolidation into one paid product and 1 or 10 licenses, who the heck needs 10 (a very large family, 5pcs 5mobiles, etc). Personally I feel there needs to be a more flexible intermediate option/s 3, 5 licenses, etc.