I have a Hinterberg Easy Build that I built myself several years ago...very simple. It sells for about $180 and you need to buy three conduit poles and the wooden trestle piece. You can cut the poles to whatever length you want with a hacksaw. I love mine...folds flat to the wall for storage even with a quilt on it, is fully adjustible, and you can mount a lamp to it.
http://www.hinterberg.com/prod-Easy_...ame_Kit-8.aspx