typically, a fantasia will include a hat, shoes, pants, an undershirt, and the main body of the costume comprising of the shoulders and the back of the outfit. 

these costumes are quite large, and have to be put together with the help of others, usually just a few minutes before getting in position to parade - much fun to wear, most of these costumes are often too difficult to disassemble, and painful as it is, taking them back home intact is almost always impossible.

some schools such as beija-flor and mangueira will sell slots quicker, due to their reputation, there are varying levels of responsibility - no matter the school, this is definetely a once-in-a-lifetime opportunity that should be done if possible.