Personally, I wouldn't buy anything just to use as a trader. The way things have been going with RCI in recent years, you can't even be assured of a decent exchange if you own at one of the best known, high demand, expensive Gold Crown resorts.
It's better to buy a week that you could see yourself using almost every year, one that would also rent for at least the cost of the maintenance fees. If you want to go somewhere else one year, rent it out and then use the rental income to rent what you want directly from an owner and by-pass all the uncertainty and drama of depending upon an exchange company like RCI.
This is what we have been doing successfully for the past several years.