re: Salt water fish tanks

Its probably more than $1000. It gets to a point where you stop paying attention to how much you spend on it I also got lucky because my buddy got tired of his tank and gave me 25lbs of live rock.

Your gonna want:
Tank - ~$300
4 bulb light fixture or LEDs -$300
Sump -$150
Good pump -$100
Power heads (I'd do 2) -$100
~20 lbs sand -$40
dosing kit -$100
test kit -$100
RO/DO water filter - $200

and then rule of thumb is 1lb live rock per gallon, and live rock is ~5.99/lb. You can slowly build that up over time though. I'd add a protein skimmer as well which is another $150

Then whatever you wanna spend on fish and corals.

Craigslist is your friend for a lot of the equipment. Especially a tank/filter.