They start at $30,000, allowing you to index up to 500,000 pages. And they're yellow; bright yellow.
I remember watching a talk by John Battelle to Google employees on my iPod Video a few months back. At the end of the talk, one Google employee asked how she might spread the word on the Google App. John's response was to give one or two to some high-profile web users, suggesting 'that guy from Fog Creek'. Hey presto, one turns up on Spolksy's doorstep. I wish he'd mentioned my name instead; or else Rob's.
