I'm not trying to scare anyone off, but it is important to be realistic.
Before you start spending, you want to have an idea of what you want your tank to end up being (reef tank or fish tank....big or small bio load).
If you want a very basic small bio load fish tank that has a layer of sand, fake plants, a few fish and a rock, then you are looking at a cheaper set up - especially if you buy a used tank.
For my personality, it was necessary to get a "classy" tank (full wood top and bottom) to house my big bio load reef community.
THE DECEPTION: The problem with owning a salt water tank is...although in the BEGINNING you might feel that you want a small bioload fish tank.....over time...as you learn more and more....the REEF ADDICTION sets in!!!! This is a reality for most sw
aquarium owners and this should be accounted for when determining tank cost.
You may originally have intended to have a small bioload fish tank when you get your first live rock. Then all of a sudden you learn about algae and coraline algae. Then all of a sudden you find things living in and on your rock - things you never even thought existed!
Then you you decide it would finally be cool to get that anenome with the clownfish (the gateway "drug" to coral).... Now you have to get the proper lighting. Now buying coral is inevitable and that low end pump is no longer going to cut it!
So, although you might see people in here claiming that a cheap tank can be done - beware! I would hate to see you go "cheap" and buy all of the small stuff for a low bioload tank only to have to throw all of that stuff away because now you want a reef tank!