Hiking and Sightseeing Southern France

We, a small group of guys, will hike and visit mediaval villiages and roman buildings in southern France like Nimes, Arles ,Avignon etc Accomodation will be in a small, romantic guesthouse in the mountains near National Park Cévennes. Our friend Tom, a student of history and archeaology will guide us. The approximate cost for the whole week for accommodations and all meals would be something around 400 Euro. I'm sorry, I don't know in US Dollars. There could be also some split costs when we share cars for the trips around.