With zoa's and plates ?? (Chalice etc) you can go pretty low tech. You do need to consider; water movement, lighting, temperature control and nutrient control.
A shallow pond will do fine, no sump required. You can get them around $200
A round tank allows for a single water mover pump the Jeboa are so seriously cheap and effective. Not much more than $100
Temp is the one to consider when expense comes in via power consumption and equipment, depending on how you locate the tank your going to need a heat / cool chiller unless it is in a very stable environment. That is the killer at $1000 but you can pick up second hand units for a few hundred $ if you keep an eye out.
Skimmer not essential but can make life easier, you can feed the corals more and do less water changes. So you can spend a few more hundred here.
As for lighting personally I like LED for heat and electrical efficy zoa's and plates can do well on relatively low lighting if fed adequately. on Ebay you can pick up some serious lights for under 200.