Join a local or regional club. It is a great way to get deals on used equipment, coral frags, and other livestock. People in my local club seem to go out of their way to help eager new people. I'm sure other clubs are similar? See what other people have that works. Spend the money to do it right -- it's way cheaper in the long run.
Your ongoing costs are electricity, salt, and foods. Probably also supplements (calcium, alk, mag) if going full reef. I suggest buying captive bred fish at first. They are hardier and when you kill them as you're learning, you won't have an impact on the ocean since they're farmed.