An off-market property is offered to selected buyers without a full public campaign. That is all the term proves.
It does not prove the home is scarce, underpriced or suitable for the brief. The vendor may value privacy, speed or certainty, but the property still needs to pass the same sequence: brief, pocket and street, land, light, location and layout, due diligence, then genuinely comparable sales.
Ask whether the vendor is committed to selling, who else has inspected and when a public campaign would begin. Treat the answers as campaign information, not proof of value.
Access expands the opportunity set. Judgment determines whether the property belongs in it.