I think the AV ap cost should scale with the virus level just like the install does, it only makes sense that it should be more work to uninstall a virus that took more work to install.
Ah you don't want that. Just simply find a server you like. Install 5 Virii on it. Start disinfect on all 5. Locate the missions for the 80% thing and kill the disinfect on the ones without missions.
Boom you have a win win scenario. Why do you think SGP is no longer putting up gobs of Virii? We are disinfecting them ourselves!