I took it down to move cross country. I moved from Las Vegas to Charlotte. I am in a rental house until my house in LV sells, so it could be a while before we get our own place here, but once we do, a new tank will be in the plans, probably another 450. I really liked the dimensions (96"x36"x32").
You are right though, the bigger the better and the sky is the limit on cost. I did everything high end and took my time planning it. It really wasn't that much work once it was up and going. The key is to try and automate the water top-off and make water changes easy. You only change about 10% of the volume per month, so that wasn't too bad. Buy good equipment to start with so you don't have to replace it once you find out you bought the wrong thing.
SW is less work than fresh in my opinion as long as you set it up right. They are not difficult either. The perfect size is really anything 180 gallons and up, the sweet spot being 180-300. There are very good on-line dealers for livestock and there are very good on-line sources of info. See
www.reefcentral.com. They have forums for newbies and fish only if you want to start out that way.
If you really are interested in SW, feel free to pm me any questions. I have been doing it over 10 years.