Exquisite Essence: 1977 gold
Iridescent Tear: 312 gold
Fiery Brimstone: 63000 gold
Tome of Black Smithing: 56 gold
Tome of Jewel Crafting: 892 gold
Tome of Secrets: 527 gold

 These prices change on a minute by minute basis. Something that is addressed by Marcko on Diablo 3 Gold Guide Blog. Which makes recording them a little problematic.  Quoting a single price gives the impression that the price was steady all day.  Which is not the case.  It makes the most sense to record the lowest values seen that day as most folks use the lowest price to get their products to move.  In addition to reporting them in the blog, there’s a google doc started to record the data.