Corals and fish dont come cheap, it might be hard to find a good one for under 15 dollars.
Lighting: a high lumen lighting with 4 wpg for very basic corals, 6 wpg for harder ones, 8 wpg for even harder ones, and 10 wpg for almost all of them. High lumen means light that most resembles the sun, it has to be flourecent or metal halide, incandescent wont do anything. Using VHO, PC or MH lighting is the most common, new T5 lights are becoming more popular now as well. NO flourecent isnt that good as getting a NO light with 8 tubes isnt that cheap and the lumen's arent as good as MH. Getting some blue antic light is also good. Moon-lights will show you the nocturnal behavior of your fish and corals so these are also recommended.
Filtration: Buying a nano skimmer like the AquaC remora series nano protein skimmer is good. Dont get the fission air powered skimmer, its cheap, but you get what you buy. A good quality HOB filter like the hagen aqua clear is more of a mechanical filtration. Use a sponge insert and clean it in old saltwater once a week to prevent the poop to raise nitrates that the corals wont like
Water: Either buy an R/O filter or buy RO water at your lfs or walmart or something. Then use a high quality salt mix like instant ocean
Live rock: Get a pack that has lots of bio-diversity that has rock from all over the world.
Sand: Nothing wrong with live sand, you could get aragonite as well, dont get crushed coral, it will trap pieces of poop that will raise nitrates and foul up the water.
Heater: Best quality one that you can find
Getting high quality stuff means spending a good lot of money, in this hobby, many people told me you get what you buy, when i start my tank i will listen to them and buy best quality stuff, even if it is expensive, i would suggest you to do it as well.