I did a quick search and found round trip tickets from Miami to Sao Paulo in March at $789 (if you travel in January, $740), inclusive of taxes and fees. While that's not exactly $500 (50K points), it isn't "well over a thousand" either. Booking on Orbitz using the Orbitz Visa, I would earn 6% back on that ($47.34) to use on a hotel booking. Do you have to pay taxes/airport fees? If so, how much? Add to that the $95 AF.
Sure, it's not the same airlines, but it's still a round trip.
Point is, there are deals to be had with cash as well.
There's another thing to consider as well: were you planning on a vacation to Brazil anyway in March, or would you have been just as content to vacation in New Orleans were this deal not available to you? In other words, are your vacations grander because of the rewards, and do you want them to be? Yes is a perfectly acceptable answer to both, but is it yours?
Overall, it depends on your goal, the ease of earning points, and the fluidity of spending them. Nothing is more fluid than cash, but sometimes it can be difficult to earn. Point values can be high but non-fluid. It's all about what works best for you.