It all depends. In the last 20 years I have had 5 tanks and have never bought a new one. My 2 current tank: 29 biocube ( 5 years ago) with MH light, live rocks, protein skimmer $150. 125 gallon ( 4 months ago) with everything (lights, stand, sump, live rocks, protein skimmer, etc...) $400. If you are willing to look there are plenty of deals out there. It all depends how much you want to work for it. I had to drive 4 hours to pick up the 125. I must warn you, buying the tank is the cheapest part of this hobby. I refuse to add up all of the $$ of have spent on Lights, powerheads, corals, sand, and fish. I wish I had switched to LED's sooner. The replacement costs of bulbs really adds up. Invest in your own RO/DI unit. Buying water at a $1.00 per gallon is another cost that can eat up your budget.