I'm going to take a cruise with family starting in Rio and turns out to be the week of Carnival (3/2010). That at first sounded like a good thing until I found out the JW is gouging us for $2K (3 in a room) a night for a manditory three night stay if we choose to stay at the only Marriortt in town. I didn't think Bill did that or allowed its franchises to do this. What's up? I don't feel safe going to another hotel.
There are many safe hotels in Rio. The Altantis Copacobana and Windsor Plaza to name a few. You can check out Lonely Planet or TripAdvisor for reviews. I agree that when I travel internationally I almost always, if possible, stay at Marriott properties. Not possible in Cambodia or Brunei but sometimes it's fun to stay in hotels that are a reflection of the culture that your in. I agree that price gouging is ridiculous and should not be allowed to happen. Maybe the Rio Marriott is not a franchise hotel and is run by a different company. Sort of like when the home improvement stores raised prices on wood and nails after and before hurricanes in Florida or the Gulf Coast. Loyalty works both ways. Maybe one of the ambassadors can help but I'm assuming that this is standard practice. If I'm not mistaken the hotels in New York, Times Square area raise their prices at New Years. Explore your other options. Sometimes change is good.
I've stayed at the JW in Rio. It's nice, but there are several other nice hotels within walking distance of the JW. When I stayed there I thought the price was high at around $250 USD per night - $2000? wow. Is it possible they were quoting you in Reals and calling it dollars (it happens quite a bit). Still $2000 Reals would be around$1100 USD - still too much.