Some macaws are nearly extinct. The Spix's Macaw has only seven surviving in captivity, with one wild bird left. Please be aware of this, and make sure you have a domestic baby, because if it's not, it's very likely smuggled. Smuggling is a problem with the Red-Fronted Macaw. Here in Maryland, where I live, everything tends to be on the expensive side, including birds.
Macaws are incredible shriekers, screamers, and callers.
Vocalization depends entirely on the personality of the individual bird. They also make decent talkers as they have clear articulation, but sound high and nasal when speaking. Macaws are curious and intelligent. They love puzzles, and will often unpuzzle themselves right out of a locked cage. Give them lots of chew toys.