Short answer: Pre-submission review cost depends on manuscript length, subject complexity, the depth of feedback requested, and whether language editing is included. It should be clearly distinguished from formal peer review performed by a journal.
A pre-submission reviewer may comment on clarity, organization, reporting completeness, presentation, and obvious submission-readiness issues. The service should state whether it includes subject-matter critique, language editing, or both.
Independent pre-submission feedback can help authors identify avoidable weaknesses, but it does not predict or replace a journal’s editorial and peer-review process.
Ask for the expected deliverable—annotated manuscript, review memo, checklist, or editing file—before comparing prices.