Not the government fees, which are set in the USCIS fee schedule regardless of work location. It does add evidence: a service agreement and reporting structure showing the petitioner retains control, which takes legal and management time to assemble and increases the risk of a request for evidence if omitted.
Offsite work is a documentation cost, not a fee
The I-129 base fee, any additional statutory fees for L petitions and the optional premium-processing fee are the same whether the transferee works at the U.S. affiliate's own premises or at a customer's facility, and current amounts should be read from the G-1055. What changes is the evidentiary burden.
Where the transferee will work primarily at a client's site, the petition must show that the employee will not be principally controlled and supervised by the client and that the placement is not an arrangement to supply labour, but the provision of specialized knowledge in connection with a product or service of the petitioner. Hypothetical example: a Sainte-Brigitte-de-Laval systems integrator is to spend a year at a U.S. utility deploying the firm's proprietary monitoring platform.
The file needs the master services agreement, a statement of work describing deliverables rather than hours, evidence that the transferee reports to and is evaluated by the petitioner's manager, and a description of how the petitioner's product is central to the placement.