I don't really know what a FO
tank is like, but I can tell you about my nano.
A year and some change ago I set up a 10 gallon nano. I have about 15-20 lbs LR
and coral. I don't have fish right now, but I did. The cost isn't that bad...you can probably find the rock for under 100. I have a (too large) skimmer that I paid $100 for. I have 2 powerheads moving water. I had about 20lbs of sand (about a 3 inch bed). The lights I have are a 24 inch satellite PC
(65W). I would definitely have gotten a different light system if I wasn't new into reefing. In all, I probably paid $350 for my setup (I already had the tank)
Now I don't have any sand except for a small layer just to cover glass. I'm about to add a 10 gallon fuge. I bought a used MH
system, but all together I probably have spent less than $500 (not counting livestock).
If you have any questions, I can try to answer them. It's only been a year, but there are things I would have done differently knowing what I know now.