No, the brokerage agreement is between the shipping company (UPS) and the recipient (you). The sender (Mim) is not involved at this point.
Somebody has to do the paperwork and pay the duty on the package. The brokerage fee is UPS' charge to do that for you, but you can do the legwork yourself.
When you get the notice from UPS that import charges are due you don't pay UPS. Instead call UPS and tell them that you'll self clear the item, and then pay the duties directly to CBSA.
- You pay Mim for the uke & shipping
- Mim pays UPS to ship, hands them the package, and is done
- UPS carries the package from WV to the border through a path that would do the Family Circus proud
- UPS asks you to pay their brokerage fee and duty
- Option: You pay UPS duty + brokerage, and UPS files the duty for you, charging a brokerage fee for the convenience
- Option: You refuse UPS's brokerage, go to CBSA and pay the duty directly. There's no broker and so no brokerage fee. You send UPS the proof from CBSA that the package cleared customs.
- UPS delivers the now-released package to you