Travel and lodging between sites are the main additions, and who pays them is an employer policy question to settle before accepting. Where clients or intermediaries are involved, budget for legal review of the contracts. Government fees vary, so confirm current amounts directly.
Settle travel terms and contract review early
Get the travel, mileage and lodging terms in writing alongside the duty description, since a broad territory can mean substantial unreimbursed cost. Contract review is the other likely expense: a client-site or intermediary structure usually needs more counsel time than a straightforward in-house role, and that review is cheaper before the assignment description is finalised than afterwards. Compare the two ways the request can be made, because they carry different cost shapes.
Seeking admission at a port of entry concentrates spending in preparation and travel; an employer petition on Form I-129 adds filing steps the employer handles and, generally, more counsel time before anything is submitted. Neither is automatically cheaper, and the choice should follow the facts of the role rather than a quoted price. Ask the employer which route it intends and who carries each line: preparation, filing, evaluation of a foreign credential, and any contract review the structure requires.
Government fees change, so verify current amounts from the official source rather than from a figure carried over out of an earlier file.