Hold on simfish,
What these guys have said is exactly right, it is a pricey activity - but my baby is still under the $400 mark:
http://www.pbase.com/chris_and_jen/aquarium
If your on a tight budget (like I'm on), you just have to scale things back a little and use a bit more DIY and creativity with your equipment.
Small and, in my case, very small tanks are not impossible to successfully run like you would be lead to believe. But they do require a little a bit more precision and thought into your stocking options.
There's a big trend at the moment in the states towards Nano (30 gallons and under) without skimmers and sumps. I know a couple people who've had their's running for over 4 years and have had great success with some sweet looking tanks.
Check out: http://www.nano-reef.com