You will always go into cost overuns with either.. Don't let your wife confuse "redecorating" with "remodeling".. two very different things. If you have a vision, know what you want and stick with it new construction will likely be cheaper than remodeling an existing place.. however, new construction limits you to very few open lots/land that are available and that land in the area where you are looking may very well price you out of new construction vs buying a used home with good bones and just needs an update. The other trap of building and remodeling are the change orders.. every corner you take in the process will provide you with oportunities to upgrade this item or that item or move this cabinet or that wall, I have seen many clients lose sight of their initial aim and get buried in change orders that turned their $500k project into a $1mil home by the time they were done.
In other words.. I would spend a few months looking at homes on the market in the area that you are looking to see what is available. There are tons of house on the market in the Evergreen/Conifer area and many have been on the market for a while. Finding a number of homes with the land and features you are looking for will give you a benchmark to work off of and you never know, you might actually find the house you want that is ready the day you move in.