Hotel or rooms or B&B will cost from very cheap to very expensive depending which country and city. Do not stay in too cheap a place in cheap countries.
Between 50-100 Euro a day for a room.
Food, tranportation, and seeing things will cost you another 50 a day.Probably less now and then and more other days.
Count on 200 a day. If you study bustours or other forms of trips you will get up to that.
150- 200 Euro a day not inculding the longdistance transportation.
200 Eur0 = 220 dollar x 30 days = 6.600 x 11 = 72 600 : 2 = 36 300 pp That is without any form of luxury.