alan:
while traveling through Scotland, with my oldest daughter ( 'bout 5 yrs ago), we stayed one night in a B&B ( which she pre-booked & paid for - and refused to tell me how $ or pay any part of!) , and then in Hostels. I think one needs to pay a nominal fee to join a Hostel association ( not sure) , BUT: very affordable/inexpensive; most had toast or crumpets & jam & coffee or tea (included) available in the morning .. also cooking facilities, secure storage for luggage, and we met lots of interesting folks, including a couple running a Hostel in Oban. The Hostel we stayed at in Edinburgh was only a couple blocks away from the castle. I would recommend checking them out - lots of info online. have a great trip!