booked this trip at Andina travel agency in Jerusalen street for 135 PEN pp.
Other travel agencies offer the same package for similar prices, but since the groups are mixed up anyway we can't say much about the travel agency Andina.
Our guide, Hubert, was really fantastic: fun, full of enthusiasm and offered on the first day a botanical tour in the valley (very informative).
3D/2N is exactly the same trail as 2D/1N package, but with less hours walking on the first day. The 2D/1N goes also in the valley but goes directly to the 'Oasis' sleeping place (lodges with pools), which means 4 hrs more walking (note: the bus picks you up at your hostel in Arequipa at 3:00 am).
All in all a nice trek in a very nice, but hot valley!
This review is the subjective opinion of a TravelPod member and not of TravelPod.com.