Breuer is one of the top estates, but the reputation was achieved by some strange lobbying and his involvement in the Erstes Gewächs, a lobby group that started in the Rheingau. In my opinion he gets a lot of undeserved press due to his connections and despite the wines being good, they are overrated and not worth the price he is asking. Sorry I disagree, but I have tasted his wines in several consecutive years in Germany at the VDP Gutswein. The better values can be found with small estates in the region that are not as famous but produce wines at least as good. Check out
http://www.vinonet.com/leitz.htm
http://www.vinonet.com/knyphausen.htm
Also check into some of the larger estates with good quality or impressive and deserved recognition due to quality and history:
http://www.schloss-johannisberg.com
http://www.prinz-von-hessen.com
http://www.domdechantwerner.com
Other great estates worth visiting are the Robert Weil estate and the estate of Mr. Künstler.
My knowledge of the estates is based on having traveled to many estates to taste and I grew up in Germany in a winery now working in the wine industry in the USA as a buyer and consultant. Feel free to contact me for suggestions for your travels and have a great time enjoying the beauty of the country and the wines.