Do
not get crushed coral. It will cause problems. You can go barebottom in a saltwater tank, if you really need to save money.
If you're getting corals, you should also get calcium and alkalinity tests.
There's an electrical costs calculator here (you'll need to fill in your cost per KWH as well, it should be on your electricity bill in some form):
Reef Central Online Community
A fish-only tank will be a lot cheaper to run (and to stock).