From The Obey Me Wiki
The Special Sales pages list all of the different in-game Flash Sales, Recurring Special Sales, Birthday Sales, and Limited Time Sales that have happened since Obey Me! was first released, and provides details on what items were available at what price.
For information on standard and VIP sales, see the Akuzon app page.
With the exception of the Flash Sales page, these pages are all currently works-in-progress!
Disclaimer: The Obey Me! Wiki is contributed to by a voluntary association of individuals (a.k.a. fans). All rights are reserved and attributed to NTT Solmare Corporation.