Get tanks off the list of craig. I got a 150 gallon with two Marineland Emperors, spare parts, two powerheads, what felt like one ton of gravel, air pump, heater, all kinds of stuff, for $250. Before I learned of the beauty of CL I paid about $600 for a 75 gallon and stand. I paid retail for a 20 and a 55 before that. I paid $150 for a used 65 gallon square by comparison
I'm going to get another 6 foot tank soon, and I'm not going to pay over $200. Just make sure they hold water. Even if the spanner in the middle is broke don't waste time on trying to reglue it just go to hardware store and get some nuts and bolts to make a spanner that you can screw on...
You can even make your own filters with an airpump, sponge, and a water bottle
Just search DIY aquarium.
The expensive thing is chemicals should you need them. Water conditioner, and I always have stress coat (I have rowdy fish) and CO2 booster for plants.
I've never done the salt water tank thing...just freshwater. Marine reef is a qualitative level of difficulty higher. I like the cichlids where the biggest threat to their health are other cichlids