The FBI won't look into fraud in the virtual merchandise market. It's simply just too ridiculous, they have bigger problems to handle.
The amount of money lost in this situation will be irrelevant to IC3. Even if it was $1000, I doubt IC3 would look into it, it is not a substantial enough amount of money to be worth tracking someone down.
Besides, the time and money spent trying to get this guy in court would eventually exceed the money you lost by far. It's simply not even worth it.
Moral of the story, you can report him, it will do nothing, scammer wins in the end. In your future prospects to dealing with people in the online market, be more careful and make sure you properly evaluate the person you are dealing with.
Sorry for your losses.