It can be done a lot cheaper, though. An acrylic SeaClear 30 gallon runs about $180. You can build a stand for well under $50; look at how your LFS does it, probably just sits the tanks on a few cinderblocks! With a $50 budget you could get something usable that won't be beautiful but will get the job done.
Factor in about $100 for a decent PC light, $10 for some eggcrate for the lid, $10 for a heater, and $50 for a good filter. I'll guess 40 lbs of live sand at $100 bucks, and 50 lbs of live rock for another $200.
That puts us at $650 plus fish and corals. It's not perfect but it'll work, and with a little effort put into the stand, can look pretty nice. I'd recommend a good test kit and a couple chemicals to get things going and maintain levels; figure you'll spend $50 there, for a grand total of $700 + livestock.