Government fees follow the USCIS fee schedule for Form I-129 or the CBP fee at the port of entry. Who pays is a matter of the employment agreement, since TN has no employer-payment rule of its own.
Separate government fees from professional and licensing costs
Hypothetical example: a Mission forester is told by the hiring company that its immigration budget is used up and she should cover the costs herself. For TN that is a negotiating point rather than a legal violation, because the rule that employers must bear certain fees applies to other classifications. The government charges are the port-of-entry application fee collected by CBP or the Form I-129 fee if the employer petitions, each set by the current USCIS fee schedule; premium processing is an optional additional fee for the petition route only.
Beyond those, she may face costs for regulator letters, transcript requests and any state forester licensing the job requires. A credential evaluation is needed only for degrees from institutions outside Canada, Mexico and the United States. Ask the employer to put the allocation in writing before the start date is fixed.
Hypothetical example: A veterinarian accepts a clinic's offer after paying for credential translations, a licence application and travel, then learns the clinic will reimburse only after entry. The first review separates government charges, professional expenses, document-preparation costs and travel from the employment terms. Receipts settle who actually paid, while the offer and any reimbursement policy settle whether repayment was promised.
A cost disagreement does not convert an otherwise valid employee into a self-employed applicant, but an arrangement where the worker funds and controls the U.S. practice can expose the wrong relationship. Resolve that allocation in writing before the appointment or travel date.