The cost can be pretty high in terms of setting. A peasant deals with bandits and fellow peasants, new laws, new taxes, and other such threats. A landowner deals with similar problems, the economic growth of their holdings, larger taxes, bandit occupation, civil unrest of the peasantry, and other laws. Nobles deal with political backstabbing and potential war with fellow nobles, the complaints of peasantry and other sworn people, and the actions or declarations of their king.
Each groups threats increase in scale as their rank increases. These threats should pose about an equal problem for them as the threats of a lower ranking person should pose in kind (so a peasant dealing with the local bandit should be about on par a challenge with a prince dealing with rival claimants; a noble warring with a noble should be about on par with a king warring with another nation).