Many hobbyist just entering the hobby will have “sticker shock” when they see the prices for good quality live rock. Sometimes this will result in some people t trying to find the cheapest approach to filtration. This is the wrong approach to take. Cutting corners on your filtration will always result in long term difficulties. The below links can better explain what I mean
https://www.reefaquarium.com/2013/common-approaches-to-filtration-in-marine-aquariums/
https://www.reefaquarium.com/2013/some-algae-scrubber-basics/
http://www.advancedaquarist.com/2003/2/beginner
http://www.reefaquariuminfo.com/the_filters.html
You mention “sticker shock” right off the bat and this might be the single-most important thing that keeps new aquarium enthusiasts from getting it right! If you take the time and do the research, as you counsel, you will find that you are money ahead to buy the better filtration system up front, rather than “cheap out” and go with a smaller, less-efficient system. In the long run, your fish will live longer and you will spend a lot less money replacing them than you would have spent buying the right system to start with! Good call, Cliff!