1. A computer implemented system that determines costs associated with updating file formats, comprising: an interface component that interfaces with a network-accessible data storage service that facilitates archival of data associated with a user and retrieval of archived data; a monitor component that examines archived data, and monitors archival and retrieval transactions between the data storage service and the user, and that identifies a legacy file formatted in a legacy format that is old, obsolete, or volatile file format; the monitor component further selects a converter from a set of converters; and an analysis component that determines a respective cost-benefit to the data storage service for each of a plurality of conversion scenarios directed to utilizing the converter for migration or conversion of the legacy file to an updated file with an updated format, where migration is directed to replacing the legacy file with the updated file and where conversion is directed to constructing the updated file that is distinct from the legacy file.