the smallest tank I would suggest would be a 30 gal
tank. But if you can go with a larger tank like a 55 that would be better. The reason is because the larger the water volume the slower the tank conditions change.
Im not sure on the evenual size of a parrot fish but I think they need a large setup.
THe price of fish and setups will vary widly depending on the area your in. I just so happen to be from staunton so I have been to c'ville and I would say your average saltwater fish is gonna run you in the area of $7-$15. Now that would be a gross average price. There will be many fish that will be above that $15 and there will be some fish below the $7 range.
Water weights 8lbs per gal
. Add a few lbs per gal
to that for sand and live rock and you got yourself something like 12lbs per gal
. Not to mention the weight of the tank and stand.
I would guess that if you was to buy a 55 gal
tank setup with all the basics you would be looking at $400 or so. You would need the tank, stand, salt, testkits, skimmer, sand, some live rock, and lights. Now I would not buy all this at one time. Get the tank, stand, salt and lights, heater, powerheads, skimmer.
Get all that working and at proper water conditions. Then add your sand and live rock. Then plop a raw shrimp or two. Let your tank cycle for a few weeks then get yourself your first fish.
I would also suggest a few books from our saltwater library. http://www.aquariumadvice.com/library.php
These will become great reference tools when your looking at what kinds of setups you could have.