Well I'm not sure on that because I don't live down there.
My friend Angel Does though and from what she tells me its Allot more expensive than tanks and filters up in the states. Just for example, the same filter up by me cost's $40 dollars less then what she was paying for it.
Guess it's cus you live on an Island in the middle of no place, LOL, kidding.
See if you can't find that stuff used, you guys have a Craiglist or something similar to that right ? Buy your tanks and stands used and you will save hundreds of dollars. Then you have more money to spend on better filtration system. But in general $300 dollars should be enough to get you a 50 - 55 gallon tank and filter.
Too bad you guys don't have Walmarts down there, they sell a 55 gallon (48Lx12Wx18H) with a filter, lights, hoods and heater for $185 dollars us.