Most of Bizz's items are simply there for flavour and don't have any function (aside from the bun trophy and the burger ingredients...), but if you're a bit of a completionist... you can either grind enemies or make use of the various coin / dice mini-games scattered around the camp! One is located within the inn during daytime, and another is located within the beach hut during nighttime.
Antiques and the such you can give it to Bizz via the 'Appraisal' function he offers when you talk to him.
-RegalBuster