Is There an Affordable solution?

Hello

I had been using the free avg for my 4 home computers. Then something weird
happened. a Few times I noticed
that when either my wife or I would attemp to download our mail using
Outllok Express, while AVG was scanning
incoming/outgoing mail it was being diverted somehow. Instead of going to
mail.comcast.net it would say something like
pizzaAD.demon.uk.....I can't remember the exact name. Basically, we couldn't
get our email for a time. Then it would go away.
I got nervous and the only way to stop that was to uninstall AVG. Now I need
an antivirus program for our small home network
that is won't cost an arm and a leg. I am using a 30 day free trial for
Kaspersky. It seems to work great, but is a bit pricey, especially
considering all four computers.

Any suggestions on what to look at and possibly buy for an antivirus
program?

And, any idea what was happening with with our AVG and email program?
Hacker?

Thanks

shawn