Though rates can fluctuate throughout the year based on tourist traffic, hotels in the city center generally charge between 100 and 150 euro a night. Venture a little ways out of the center and you'll find rates around 70 euro or even less.
You won't find any traditional bed & breakfasts (think charming cottages with sprawling communal breakfasts for all of the guests) in Croatia. However, many hotels provide a buffet breakfast, and sometimes - if you choose wisely - your private accommodation host might provide breakfast. This is an unusual perk, however. Breakfast is simply not a significant meal in Croatia, and though there are a few exceptions, it's assumed that tourists staying in private accommodation will feed themselves.