The driver that we used in the Sacred Valley is Sabino Chirinos and his email address is
[email protected]. Just mention that you got his name from guests at the Tambo who he took to Maras, Moray and Chinchero. He speaks English and will work with you on price. He offered to do pickups from the Cusco airport and he lives near the Tambo in Urubamba, so I'm sure he'll be available for car service in and around the Sacred Valley. We wanted to see the countryside, but didn't want to pay the Tambo tour rates ($150 pp), so Sabino was a great option for us.
Platinum treatment was wonderful, but I suspect that they will treat all guests well. The staff is well trained and anxious to make the hotel a premiere destination in Peru. Be sure to stop by Kiri bar and talk to Fritch. He has some great stories.