An initial review can identify gaps, but clarify which facts and records need confirmation before extensive drafting. Ask what the quoted scope covers.
Pay for an accurate assessment
Separate official charges, evidence review and document preparation. A more expensive or longer letter does not guarantee a stronger case. The company must supply genuine facts; an adviser cannot create missing employment or knowledge history.
Ask for the scope in stages rather than as one number. A workable division is an initial eligibility and records review, then the corporate and employment evidence, then the knowledge description, then the filing itself, then responses to any later questions. Each stage should say what it produces and what it assumes.
Hypothetical example: a reagent manufacturer accepts a fixed fee quoted before anyone has read the training records, and the records turn out to place the applicant on the relevant product only in the final months of the qualifying period; the work then doubles and the quotation covers none of it. A short paid review that reads the records first is usually cheaper than a fixed price that has to be renegotiated halfway. Confirm official charges from official sources at the time of payment, and remember that no fee, however large, supplies employment history or knowledge the company cannot evidence.
Ask what the review would cost if it stopped after the first stage.