noun
finder's fee
A reward or commission paid to someone who finds or introduces a business opportunity, lost item, or similar.
落とし物を届けたら、発見料をもらった。
When I turned in the lost item, I received a finder's fee.
不動産会社に発見料を支払う契約になっている。
The contract stipulates that we pay a finder's fee to the real estate company.
手数料 is a handling or service charge, whereas 発見料 is a reward for discovery or introduction.
Compound of 発見 (hakken, 'discovery') and 料 (ryō, 'fee').