I think that the main reason for the hoard of treasure is simply to satisfy the audience, as gold is kind of a staple in Anglo Saxon culture. But I think it could covertly signify Beowulf's pride in his long heroic life span, that has lead up to this final battle to the dragon that guards that treasure, or his pride. As soon as Beowulf, not single-handedly even, defeats the dragon, he frees up is pride, and looks sadly at the freed treasure, like we talked about in class today. He could be realizing how unimportant treasure is and also his own pride, and realizing that he should have heeded Hrothgars warning so many years ago. The treasure itself seems unimportant as well as the pride that leads to Beowulf's own death.