The surprising thing is that this isn't really a brand new idea.
If you go to the website for Bullseye Outfitters (an outfitter used by Ralph and Vicki of the Archer's Choice and some of the other popular pro hunters) you'll see that they offer a 5 day traquilizer dart rhino hunt for $6,900.
http://www.bullseyeoutfitters.com/africa_hunts.html
This hunt has even been featured on American Archer on the Outdoor Channel recently. Yet I havn't heard a big backlash against it.