We will be in Cusco for 2 days in early October 2014. Four of us want to do the mountain bike ride tour to Maras, Moray & Salt Mines. Do we need to book this in advance? Or can we just find a tour company in the plaza when we get to Cusco--that will arrange this the day before we want to go? I have inquired online from a few companies and they want me to wire them the money for deposit (it's a $45+ fee for the wire). Or 18% surcharge on credit card and no refund of the money if we have to cancel due to illness. I prefer not to do this and just pay when we get there. Will we have any problems finding availability when we get there? Are there plenty of tour companies that offer biking to Maras & Moray?