Great question to ask. Price is definitely a factor when trying to get into the hobby, but there really is not a set price point to expect to pay. Quality of parts, used, new, automated all make a huge difference.
it all really depends on what you want to do with your tank. Fish and coral excluded I spent around 5k all in including tools and material to build my stand on my 125 gallon. This includes an apex, 2 apex dosing pumps, Apex ato, apex wave, trigger sump, custom saltwater mixing station and a 55 gallon drum for fresh rodi water. it was about 3.2k, but i recently upgraded my 3 mars aquas to radion g5's.
Fish and coral I haven't really kept track. I would probably put that to around 2k.
Honestly looking at prices of tanks of similar size with stands and a canopy with no equipment I think I did pretty well.