The one day rout recommended by the park administration (1 then 6) is approximately 12-14 km. 1 until it changes in to 6 is 7-8 km. The steep climb is about half an hour long. The total walking upwards time is approximately 2.5 hours.
The rangers hut is better than the shelter, it can contain up to 12 persons and there are matrases there so you can sleep comfortably. You should take the food with you though.
Here is a price list which I received from the park:
Prices - 2007
Services
Overnight Stay (Tourist shelter) 10 Gel per person per night
Overnight stay (Tent) 5 Gel per person per night
Guide 33 Gel per day
Horse 40 Gel per day
Euqipment
Tent 7 Gel per night
Sleeping bag 5 Gel per night
Back pack 5 Gel per night
Camping mat 3 Gel per night
Marelisi Guesthouse
Overnight stay 20 Gel per person per night
Breakfast 5 gel per person
Lunch 6 Gel per person
Dinner 10 Gel per person
Borjomi Guesthouse
Overnight stay 60 Gel per room for 2 persons
