I agree not to do this as a day trip. I am usually vehemently opposed to group tours, but, upon the recommendation of another traveler, we took an overnight tour by bus. The scenery was ok for the most part, but the best part of the bus ride was the guide's 3 hour lecture about Meteora. We stayed at a decent hotel in Kalambaka and had plent of time to walk around the night before going to Meteora. I think we paid around $75 for the both of us for everything, including dinner and breakfast. Please be aware that at Meteora, women need to be wearing long skirts/dresses (no knees showing) - no women's pants allowed. They will have long black skirts available if you don't bring one.