To hike the Inca Trail, you must either take a three-hour train ride from Cuzco to the km 88 marker or come by way of private vehicle along a dirt road to a secondary entrance at km 82. All hikers must use the services of a licensed guide company.
Our Utah travel agent planned a 10-day trip for us, which cost about $2,000 per person, double occupancy, including airfare, hotels, about half of the meals, park and museum fees, a terrific half-day river trip on the Urubamba, as well as the services of Southern Cross Adventure tour guides who were with us from the time we landed in Lima until we departed.
It is possible to make the trip more cheaply. We met a young couple from Georgia who found a bargain on airfare to Cuzco. They wandered around the town square in Cuzco and found a guide company willing to take them on a three-day trek for less than $100 each. (A word of caution: They came from sea level and only allowed themselves a couple of days in Cuzco, not enough time to get used to the altitude. They became sick on the hike.)