Mostly time: gathering structure charts, continuity records, and written confirmations from a corporate team that has just finished a transaction. Ask for an itemised scope covering corporate evidence, the duty statement, dependants, and responses to later questions, and confirm official charges at the time of the relevant step.
Price the corporate work separately
Ask the quote to identify corporate-relationship review, foreign-employment reconstruction and knowledge evidence separately. The work required depends on the transaction and the records available; technical evidence may still require substantial attention. Confirm what is billed if an early review finds a relationship or employment problem, and which later steps are optional rather than assuming the entire package must proceed.
Add one further item to that itemised quote: an early, narrowly scoped check of the applicant's own history, taken before the corporate work expands. Time already held in L classification, a period on a different group entity's payroll, a secondment, or earlier work in the United States can each constrain what is possible regardless of how the corporate chain resolves, and that answer is cheap and quick. Hypothetical example: a loyalty-platform specialist's employer commissions a detailed corporate-relationship review after an acquisition, and the history check performed afterwards establishes that prior classification time limits the assignment substantially, which would have changed the scope of the corporate work had the order been reversed.