The more east you go (on average) the cheaper it gets.
Main cities are more expensive than the countryside around it, and the countryside away from the main cities is even cheaper, unless it is a tourist hotspot.
Hostels, doing your own cooking and not much for sight seeing and drinking, about $US 100 in Western Europe, average.
Towards the east the prices are lower and it can be that $US 75 is more than enough for the same kind of trip.
Average tourists in the west seem to spend $US 400 to $US 600 per day, (again lower in the east, but I do not know how much.)
If you are rich, you can spend way more, easily.
That always dépends on the depth of your pocketbook: you can go backpack and cheap hostels or you can go five star h?tels etc. I figure you would need at least 100 euros per day for lodging, food, local travel, muséums etc
It depends on how you travel, what kind of accommodation you use, how you get around.
Compared with where?