One aspect of the invention is a travel pricing system comprising a data store and a server coupled to the data store. The server is operable to receive new reservation data that conflicts with old reservation data in the data store. The new reservation data comprises a plurality of new attributes. The reservation data in the data store comprises a format and a plurality of old attributes. The server is further operable to associate the new reservation data with a time stamp, and add the new reservation data and time stamp to the data store without modifying the old attributes.