I think Hal has the right idea as well. There is no way you can track down the buyer and charge him with receiving stolen property since that would necessitate charging your brother with stealing it.

I think that there needs to be a family pow wow about the incident. You need to come up with an honest itemized list of what you had and what the condition of the items were. Once that is done you can begin to get an idea of the value of what was stolen is. This is what should be presented to the brother and your parents so that the reality of what was done can truly set in. Then a schedule of restitution should be set. If your brother resists this he is a self centered sociopath and is beyond help. Your parents should realize that anybody who would do this to a sibling, who is off on an altruistic mission taking care of a sick child, is the type of sibling who would argue over the family will before the body is cold. If he had that little respect for you he would probably exhibit the same lack of respect toward anybody else.

At age 23 this clown is a real piece of work. If he was forced to hunt through eBay and replace one piece at a time until you had a reasonable replacement of your collection he would understand the value of the things you prized.

The only other question I have is what the little @#&$!* did with the money? Buy beer? Drugs?