I don't consider SW reefs difficult to maintain. Setting it up right the first time is important and there is a method to the madness. For a 90gal one can pay ~$10K retail for everything. All I can really say is research, research, research and be patient, patient, patient. Doing this for a living, not many do
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I would strongly recommend joining a marine fish club and online forums in order to get to know what other "reefers" are doing and get some ideas/feedback for your set-up as well as getting to know the lingo.
In terms of supporting equipment, there are sooo many products, methodologies and experiences out there. What I do will differ from what someone else does yet achieve the same result. Again, knowing more of different methodologies, who's doing what and products will help tailor a design for your particular system.
It's not a cheap hobby to get into but very rewarding as well as addictive.
HTH