Expect association fees for good-standing letters, possible credential evaluation, travel to the port of entry and professional fees for preparing the package. Government charges are set out in the USCIS fee schedule and at the port of entry.
Budget for the proof, not just the admission
Hypothetical example: the applicant assumes the only cost is the port-of-entry charge and is surprised by the association's fee for an official confirmation letter and by the U.S. firm's request for a certified copy of the licence. Small charges add up: a good-standing letter, notarized copies, a courier for originals, and if the applicant later needs a state licence, examination and application fees that the immigration process does not include. If the employer files Form I-129 instead of the port-of-entry route, its fees are on the USCIS schedule and the employer normally pays them. Ask the employer in writing which of these it will reimburse and whether reimbursement depends on completing the assignment. Keep receipts separate for the immigration package and for the state licensing steps, because they may be treated differently for tax and reimbursement.
Hypothetical example: a surveying practice promises to reimburse the applicant after the first client invoice, but the assignment is postponed before any invoice issues. Reimbursement is a commercial term, not evidence that an immigration expense has been paid or that the engagement exists. Ask for a short written list separating the port-of-entry charge or petition fees, credential records, travel, and any state-professional compliance costs. Decide which items the company pays directly, which it repays, and what happens if admission is refused or the start date moves. An opening file audit should assemble a budget with receipts assigned to one category. Trouble follows when applicants charge personal moving expenses to the employer and later try to describe them as filing costs.