With all due respect, the paradigm you suggest is at odds with itself. Coral is the most expensive, requires the most care and expensive equipment. If you want to start off cheap go with FO
and work your way up to a reef setup. The lighting, filter, and just about everything else can be achieved with much lower quality equipment.
You can run a non-reef tank with nothing more than fake ornaments and a HOB
filter. Or just a HOB
for that matter.
No matter which way you go, you are correct S L O W L Y is the operative word.
Again, the advice is based on your number one priority being cost.