I wonder how fast a good designer could bang out a favicon (given a source image)? My gut estimate is 30-60 minutes at a bare minimum. If so, they'd probably want to charge more than a few dollars. But that could be a fun side project for a designer. Set up a site and let people queue up requests, then when you get some time, just open up your backlog of favicon requests and churn them out for 10 bucks a pop.