I am 17 and have a 70 gallon reef. It has cost over 3 grand, all out of my own pocket (thanks Albertsons). This is a very expensive hobby and it does take a lot of research and effort to get going and be successful. Some advice:
1. Get quality equipment. Please. You will save tons of money in the long run. This is especially true with lighting and skimmers.
2. Ask lots of questions and most importantly, read, read, read. The people on this board have nothing to gain from giving advice. You will learn a whole lot on message boards.
3. Don't believe everything you read. For example, Marc Weiss products are worthless despite the fancy advertising.
I got my tank almost a year ago, after months of planning and saving up for it. I have purchased most of the livestock at the LFS, but most of the dry goods and equipment online because it is much cheaper.
It is almost impossible to have a reef, or even a fish only setup, without a job. Work hard and you will reap the rewards.