I really admire your approach to this. Making guides should not only improve your credibility but also overall help reduce the market of fakes by reducing demand.
That's why we never considered charging for our guides, even something as little as $1 → The point was to allow people to inform themselves about fakes, with as little friction as possible
That way, if we bump the % of people who get scammed by even a few negative points, we'd still be happy for a positive contribution