You have far more free options than the consulting companies want you to believe. Start with your pre-health advising office, whose actual job is reading applications and who costs nothing. It is the most underused resource in pre-med and often better than paid help.
Then swap reviews with other applicants, trading a read for a read in the r/premed personal-statement threads, on Student Doctor Network, or in a premed Discord, because a fresh set of eyes catches what you cannot see in your own writing. Free mentorship programs will pair you with a medical-student mentor who will look at your work, and your campus writing center will fix clarity and flow even without knowing medicine.
For a strong first pass, read a few accepted personal statements to see the bar, tighten the draft yourself, then save a human reader for the final look. Paid review is polish, not magic, and you can get most of that value for free.