KnowToday
http://www.knowtoday.com/

"Your information and research marketplace"

An auction site. The questioner makes an offer and answerers counterbid until the questioner picks one of them.

Most answer sites go out of their way to protect the user's privacy. This one goes a step farther. It positively forbids users to reveal their identity outside the community and automatically erases URLs or email addresses they might try to post.

There are no archives to browse, or I couldn't find them. Only questions currently being asked are on display.

It pays the price agreed if buyer is satisfied.