Over the years I've learned there is one thing that has saved me more money than anything else, keeping my parameters in check. Since I've focused on that I've lost a lot more live stock. To me losing a $200 coral is the same thing has buying $200 worth of metal halide bulbs. Spending money on things like supplements, quality testing equipment, keeping bulbs replaced, ensuring minimal salinity swings, and propper flow can reduce the amount of money I spend in this hobby. I see a lot of people buy corals and other live stock when their tanks are not setup to properly care for them. Or spending hundreds on water changes and chemicals to get rid of hair algae because they don't think they need a RO/DI unit. If your tank parameters are good to go your corals will grow and you can frag them to make some money and this will help your tank support itself.
So I know what I said above is not a way to save money instantly but in the long run it will save you money.
