Putting in order what they said over the long chat, it seems that the main point was that they wanted me and my followers to become their subordinates—which appears to mean their slaves, by the way they speak.
Also, "There is news in support of the fact that the inferior humans are preparing an attack soon aimed at getting the elves' treasure, and to make some preparation, we wanted some strong pawns".
They concluded that I, who had killed the original Lord of the Mountain "Red Bear"—it seemed to have become a rumor lately. Well, a black Ogre wearing armor made of Red Bear fur would stand out—who had in turn preyed on the elven hunters, was the one most suitable.
The reward they offered was a large amount of food to be shared among the goblins, and a [Unique] Class magic item or two elven beauties for me.
This, is an exceptional reward for an ogre (or so it seems. According to Gobujii anyways).
Buying a [Unique] class magic item, even the worst of them, would cost over 10 million gold. And of course, the price varies by a lot depending on its abilities. It seems some are items that are worth more than 30 million gold.