I'm guessing from the way you phrased that that you don't actually have any idea what it takes to run a site like this. It's more than just out of pocket costs for servers etc, is your time not worth anything to you? Mine is worth a lot personally, you want to pay me by the hour you'd better have a fat wallet.
Robin, you should just run banner ads if people want to pay you for them. Just make them non-nasty, host and serve them yourself, no scripts and tracking bullshit, and call it a day. That should be good enough for this cottage industry.
Thanks for answering the shop question, makes more sense now. I don't know that it's useful for me, but I'll try and check it out further.