Green Valley Ranch has gone through a lot of turmoil in the past few years with their property values declining heavily due to a lot of foreclosures, short sales and distressed sales. I would say that if you are planning to live there for a long period of time (at least more than 5-7 years) then you will have a good investment. You will probably pay a lot premium to live on the golf course. However, in the long run having a home on the golf course should add a lot of value to your home.
If you have any questions about Green Valley Ranch or buying new homes, feel free to contact me! You can go to my website to read about buying a new home: http://www.leslieheldenbrand.com/buying-a-new-home.asp