The easiest way to save money is on the tank itself. A new 200g tank and stand will cost in excess of 1500-2k+. With a month or two of patience you can get the same tank for 500 used. It will probably be undrilled, which will cost around 100 to remedy. After that you can buy a 55g used tank and build your own sump for 50. It doesn't matter if it's scratched because it's hidden anyway. Plumbing will run you another 50-100 but you can do it yourself in an hour or two. Pumps I always buy new but sales are super common; 100ish for return pump, about 40ish for each circ pump. You can save on lights by building your own LEDs or buying used. It really depends how much light you want and what you want to keep. Starter lighting will run about 100-200 + 40 for a hanging kit. Everything past these essentials are luxuries. You don't really need them, but they help reduce the workload for you. People have plenty of success without skimmers and some even prefer it.
One thing to keep in mind is that the tank, stand, sump, and, generally, plumbing are one-time investments. Unless something happens or you physically upgrade, you don't have to buy them twice. Bulbs get replaced every 6-12 months depending on usage. Pumps get replaces as needed, typically every 5 years or so.
Tank 500
Drilling 100
Pumps 500
Sump 100
Lights 200
Total 1400ish
General month to month upkeep: salt, water, electricity, part replacement alottment = maybe 200.