Epic material spreadsheet: Epic_Calc. Version 1.2. All hero epics (including Grog-Gnog). Updated 12/22/17.
Enter your current level of the epics of each of your heroes. It tells you the mats that are required to max your epics. If you enter how many mats you have, it will reduce the total needed. It requires Excel.
Thanks to @Foozle for the original idea and @itirnitii for the material lists. Note: It requires Excel.