Generic "Sports Equipment" (HS Code 9506.99.0000) should be 10% duty plus 7% VAT on the declared CIF value. So about $19 if we take $104 as the CIF.
Then of course DHL have their fees to add on.
The problem is, of course, they have the money so there's really no reason (by their thinking) to actually do anything about giving some of it back.
How much is your time worth?