Almost nothing. The early work is free requests and careful reading. Paid work such as credential evaluation and professional review belongs after the disqualifying questions have been answered.
Spend after the free checks, not before
Government charges for this route are published in the fee schedule and should be confirmed there when the request is actually made, since they are revised periodically and differ between the port-of-entry route and an employer petition. Those are the last costs in the sequence. Before them come the costs a household controls: a credential evaluation where a degree was awarded outside North America, licensing or registration where the destination requires it, and professional review of the file. Each of those is worth paying for, and each is worth paying for only after the free checks have failed to disqualify the plan. Spending on an evaluation before confirming citizenship is a common and avoidable waste.
The first cost review should separate refundable investigation expenses from spending that cannot be recovered. The current government fee table settles filing charges; an evaluator’s written scope settles the price and turnaround for a credential review. Put each cost beside the eligibility question it answers. If citizenship, profession, or employer structure is unresolved, do not authorize downstream work merely because a recruiter has a deadline. The decision is whether the paid step will resolve a live issue or simply decorate an untested plan. Hypothetical example: an occupational-health specialist delays a translation order until a transcript confirms that the course of study matches the credential required for the proposed role.