We went with Fantasy back in '01. I thought it was expensive at $100/day but some of the tours we went on would have cost us in excess of that. So, overall, if you are afraid of going by yourself, sign up with a company. You will find that they will stay somewhere a little to long and not stay long enough somewhere else.
You could get the brochure from a travel company and then do the trip on your own time following their itinerary.
The roads are something else. This year the road will be real good, next year not so. They are continually working on the roads so you don't know from one year to the next which one will be torn up