I am not THE expert as is David Pine, but I can second his opinions. Although I have been doing photography for 49 years, some of it as a professional sports photographer, I am a relative newbie in the Real Estate market. I bring not only my photography skills (whatever they may be) but I am also a licenced Real Estate (RE) Salesperson. I know from that side that RE agents are frugal, to say the least. You do need some skills to pull this off as well as the proper equipment. I have a good friend that is also in this market and he charges $$$$, but he is shooting million plus dollar homes and he is exceptional at his job. Some jobs require a lot of pre-work, setup and staging and can consume quite a bit of time. My forte is the middle of the market, the average home that doesn't get all that extra work, but sells for enough that I can get a decent paycheck if I work at it and produce good work -- work that helps the property sell. IMHO that does not include portraying the property as something that it is not by manipulating the photos, but trying to keep them very realistic while still showing the important and/or unique features of the home. I do use HDR; however, my goal in it's use is that the observer not really realize that I have done that -- a very subtle use to balance indoor and outdoor lighting. Best of luck.

A simple solution for rooms showing windows, I use manual metering and meter the outside (go to window and aim your camera outside), (make sure your shutter speed is low enough for your flash, most cases 1/250 sec. or slower) then back up to show the whole room, do not change your camera settings but turn on your flash to TTL and aim flash up and behind you, this simple approach will give you balanced soft light in the room and a perfectly exposed exterior view through the window. Also make sure your ISO is set so that you will include interior detail, play with this until you get that perfect balance. That's why digital is so nice, you can change settings and instantly see your results. By the way, that 4 million dollar house was probably shot by a pro using gads of equipment you can only dream about owning.