It can't be done for less unless you want to do it right. We started our 55 gal
tank 8 months ago and learned our lesson!
We started with $1000.00 tank and stand, canister pump, no skimmer, live sand, a few fish... It was a learning process and I wish I had known about this site earlier...a lot of our fish died during the learning process.
What we learned:
1. Large wet/dry filter works best because it gives the bacteria a place to grow and bacteria growth is ESSENTIAL when starting a new tank. Wet/dry filters are pricey.
2. You have to have an adequate protein skimmer.
3. You can't biologically overload the tank and must be careful to add only a fish or two at a time every couple of months until your tank is done cycling.
4. You have to test the water weekly in order to determine if your chemical levels are correct.
5. You have to change the filter weekly and clean the tank weekly during cycling. Cleaning involves removing problem algae and fanning the rocks and substrate with your hand so you can get the excess biological material "waterborne" so the protein skimmer can get at it.
6. You have to change 10-20% of the water on a monthly basis. And you should use bottled water.
7. You have to learn not to over or underfeed the fish for fish health AND tank health.
8. If you purchase a fish from a fish store, make the fish department helpers feed your fish before you purchase it (and you need to watch it eat) - don't buy a fish that isn't eating.
9. When you buy a fish at a fish store, make sure you are buying a healthy fish. Sometimes fish stores will "hold" a fish for you for 2 weeks after you have paid for it to ensure it is healthy. You can set up a small quarantine tank at home (which is pricey). Never purchase fish from a tank where other fish are dead on the bottom of it - even the tanks where there are lots of cheap damsels.
You CAN chance it and put the fish directly into your tank - but you risk all of your fish getting sick and dying if you introduce a sick fish into the system. It is very difficult and expensive to cure sick fish.
10. It takes TIME for a tank to "cycle" (meaning that there is enough bacteria growth to sustain the biological load). Cycling can take up to 6 months or sometimes longer. You have to be patient. You can't go out and buy a bunch of live rock, coral and fish - at the beginning one fish (or a few very small fish) and one rock. You HAVE to be patient.
11. Read and research as much as possible before you start your tank. Don't listen to store clerks until after you have done your research. You will hear a lot of conflicting advice - but once you become more knowledgable then you will know which store clerks to rely upon for advice and which ones not to rely upon.
12. Hold off on coral until the tank has cycled.
13. Make sure your fish, coral and invertebrate species are compatible - it is best to decide ahead of time what type of tank you want before you start buying. For example, DON'T buy an UNDULATED TRIGGER unless you want a one fish tank!!!
I don't know everything...and some of my advice could be wrong - but this was our experience. We lost a lot of fish after making some stupid mistakes. We learned our lesson. Fish are expensive...and it all adds up if you don't do it right the first time!!!