ROI/valuation of web site

I have a friend who has an unmaintained little web site, he's not interested in working on it any more. The site generates some income from google ads.

I have some ideas for the web site and I can work on it to increment traffic etc, so I'm interested in buying the site from him.

This is a simple valuation question; if the site is generating, say, $1,000 a year in revenues, what would be a typical price for it?

I know it depends on publicity projections etc, but to simplify let's say it's going to keep like now for a few years. The domain name alone is pretty good too, but let's also disregard it for the moment.

I have an estimate in mind but I wanted to get some ballparks from other opinions.