Trust points would be a good indicator to determine whether a user is that trustworthy. Although, there are people here who are trustworthy but are not having trust points. But it would be understood already that you are just wanting for assurance so it should not be surprising if you would look in such aspect. Also, trust score is not enough, check who gave him the trust point, it is a matter of checking the credibility of a trust point which would further give weight to that point. If that person who gave him trust point is having a good image or simply if he is wellknown in this forum, it would be safe to make transaction to that person who earned the trust point because those who have good image in this forum won't give points if the user do not deserve it.