Well, I'm just gonna start off saying it is expensive. However, you were probably scared away because of all these expensive things you need to get. The good thing about a Nano tank is that they don't cost as much.
Here are some common things you'll find online about Nano's (These aren't really true.)
-They are really hard
-Too expensive for such a little tank
-You can't keep any fish in them
-Water parameters change fast (Which is true to a certain extent.)
As long as you keep up on your maintenance, you'll have no problems.
Here is a basic rundown of the price:
Tank- Already Have
Dead Rock- $25 http://www.amazon.com/gp/aw/d/B006D5...&pi=SX200_QL40
. You can add a piece of live rock from your LFS
to spread Coraline.
Sand: $10 Buy it dead, don't fall for the "live sand because it's wet" hoax.
Lights- if you plan on growing corals, at Taotronics panel is how you want to go. $100
Heater- already have
Refractometer- $25 measures salt, don't buy a swing arm hydrometer.
Powerheads- Koralia Nano 240- $20
Filter- AC HOB
70 - $40
If you already have a filter, just tell me what it is.
Test kits- API Master test kit will do you good and Phosphates. $25 + $10
If you plan on reef add: Calcium, Magnesium, Alk
, by a better brand like: Red Sea, Salifert or Hannah Checkers.
You can slowly advance to a reef later on.