My friend and I will be in Spain mid March. Our itinery is to travel from Nice to Barcelona and then onto Granada and finally Madrid. Would somebody tell me where I can find out information as to the cost of travelling between these cities and the frequency of the bus service.

As we're on a tight budget, we had planned to stay in hostels. However after reading great reviews of the Banotel, we were thinking about using that instead. How does it compare pricewise to hostels. I'm still a little confused as to how they work.