First clarify the actual occupational fit and specific evidence needed. Not every credential document serves the same purpose.
Define the evidence purchase
Separate appropriate evaluation or translation work, professional preparation and current official charges. Spending on a document does not make unrelated duties fit a listed profession.
Ask which supporting documents this specific profession and process require rather than purchasing a generic package of translations or evaluations that may not apply. Government fees follow the current USCIS fee schedule and depend on whether the employer files Form I-129 in advance or the applicant presents evidence directly at the port of entry. Cost rises with the number of open items: rewriting a duty letter, obtaining a credential evaluation, or resolving licensing status all add work beyond a straightforward filing. The actual agreement and service scope determine payment obligations; a renewal clause does not explain every government or professional charge. Separately price any required credential evaluation, including the TN rule for degrees from institutions outside Canada, Mexico and the United States. Do not forget the state side: if the role touches engineering sign-off, licensing or exam costs may arise, and those are professional-practice expenses rather than immigration expenses.