If you think your time is that worthless, and you're happy to accept that anything that goes wrong with their PC after you've installed stuff is your fault (regardless of what they've actually done) then go for it.
Actually puki, I think you're on to something. Seriously, you could make some serious money there, and if you put a disclaimer in your contract, the customers won't have any damage claims on you.
One thing though: I'm not really sure about the potential legal repercussions of using any APPs, freeware or otherwise, for your own personal financial gain. Just check the EULA of the APP before you use it, okay? Don't get yourself slammed, mate.