Below is a summary of all materials required to upgrade epics at various levels. If you see something that doesn't match your actual amounts, please let me know. I've highlighted in Yellow the ones that seem unusual. We've discussed some of these in the past, and are waiting for a response from DB as to whether they are errors. The odd ones are where Frozen Steel is showing up in Level 9 where you would expect Iron or Grave Iron, Crystal Totems showing up in Level 4 for Dark Heroes where you would expect Shadow Totems, and Flame Etched Bars showing up in Level 10 where you would expect Etched Bars that would match the element of the hero instead.
Thanks to everyone who contributed data!
Update: In the latest update there were some changes to make the materials more consistent for the given element of the hero. They didn't give specifics, so I can't really say what information is now incorrect below. I'm guessing they may have corrected some of the items in Yellow, but can't be sure. If someone can check against their epics it would be great (if/when you are at the right level of epic). I'm pretty sure the "flame etched bar" inconsistency is still present, but am hoping at least they correct some of the other ones, especially the use of Crystal Totems in dark heroes and Frozen Steel in a few places where it didn't make sense. I've heard that they corrected the use of Crystal Totems in dark heroes, but I saw that Shade still used Crystal totems for level 4, so either they didn't correct or they corrected for Brom and Kobal but didn't correct when they released Shade.
Igorak Update: Igorak follows exactly the same pattern as Icebloom and uses Mysterious totems. Yorick uses strange totems instead, but otherwise all other materials are the same for all three water heroes. I don't know whether these inconsistencies are intentional or accidental.