Not trying to shoot you down either Phong, just saying it's possible. I started when I was 19, in college at that:
50g reef tank:
30g(50g) tank- ~$30 ($50) used? Craigslist, BAR, RC etc (I started w/ a 30g)
2x mj900-1200 ~2x$15 used
heater ~$10? used
2x96W pc ~$50 used (it's all just about waiting for a good deal/nice person)
sand ~free-$20
rock ~$50?
Puts you at $210. Not the cheapest, but definitely a doable, all-in-one tank. Granted when I started I had free water from Scripps pier, but still, it's doable.
Corals and fish are another $100 or so, unless you want all the high-end, LE, collector etc etc corals. I was happy with xenia, gsp, random palys, monti caps, everything that gets pif'd, dbtc'd, garbage disposal'd.
EDIT: Just to give reef some inspiration of what you can do on a budget, here's my first tank: