Review the actual new scope and evidence needed.
Separate transaction work from prior preparation
An old quote may concern a different employer or role. Confirm current applicable charges and professional scope without presenting a universal acquisition-related TN fee.
Expect legal review of your current status and the proposed route, possible changes to return travel, and the cost of retrieving credential records from Canada. Separate the government charge for the chosen admission or petition process from professional fees, document retrieval, any required translation or credential evaluation, and travel. If the employer is requesting the travel, ask in writing whether it covers changed flights, extended accommodation, and legal fees should the return be delayed or a new filing become necessary. An evaluation may be required, but buying a generic report before identifying the needed evidence can produce a document that does not answer the relevant question.