I went to Cappodocia two weeks ago and I drove. It was 2000kms round trip. We stayed over in Afyon and Konya on the way there, had four nights in Goreme and a night in Egirdire on the way back. I would recommend driving as you see so much more and would never go on the bus if I went again.
I think the coach journey is approx 14 hours with regulat stop offs and the buses go overnight. I think the fare is about 75 lira each way. The bus stops at Nevsehire and you
transfer onto a dolmus to whichever town you are staying in.
Personally I would recommend Moonlight Cave Suites in Goreme. They are beautiful and very well appointed and located.
The trips you can do there are 50 euros per person and involve alot of walking and the usual carpet shop visit etc etc.
Its no problem driving as the roads are very quiet once you get out of the towns. Konya is a great city to visit and the Mevlane museum is really good, as it recounts the history of the whirling dervishes. Egirdire is similar to the Lake District and the views from our
hotel (Fulya Pension) were spectacular.