In NDS the costs set to feeds included in the recipes can have different origins.
With the term cost origin we mean the context in which the cost of a feed has been set. It can be:
1) working group based: since the feed is shared among all working groups, it can have different group costs, one for each Working group. It always uses the cost of the Working Group in which you are operating;
2) farm based: this kind of costs can be used in a structured farm context only; a feed can have several farm costs, each one available in its farm only. In other words, the feed may have many different costs based on the number of farms in which it is used;
3) user list based: these costs are shared among Working groups and can be assigned to feeds that belong to one or more user lists. The same feed can have many personal costs based on the number of user lists to which it belongs.
The Update Costs function in the Costs tab provides an environment to manage all these feeds costs, if the feeds are assigned to one or more lists (working group, farm or user).