I will be staying in Siena for 3 days and want to do a day trip to Pienza and Montipulciano. I've already booked a private tour for $500 for the day but it is really more than I can afford (I do not have any money down on this tour). Now I see that there are buses from Siena direct to Pienza, also there's a bus from Pienza to Montipulciano and another bus back to Siena. Although there seems to be large gaps between these buses, the times are not bad for me (saw timetable on Siena Mobilia). My question is should I keep my tour or cancel and depend on these buses. Are these buses dependable? Does anyone have experience taking them -- I'm going in July 2014 so will they be extremely packed and hot and uncomfortable? Also, my tour is about a month from now. If I cancel do you think this operator would be able to rebook or is this not enough advance notice.