Problems with Buddhist groups
You will find the best people and the worst people in spiritual
groups. The best people are seeking something beautiful, or
trying to serve. The worst people are drawn to spiritual groups
because it helps disguise their selfish nature.
Money - Spiritual teachers and centers have expenses. It is
reasonable to charge some fees for some services, although my favorite
groups are totally free and operate on donations. I once visited
a group listed here that said you could gain merit to get a better rebirth by
donating to their group. I think that is a bad sign.
Ask lots of questions.
If you are uncomfortable talking openly in a group about what you truly think, that is a bad sign.
If you talk about what you truly think, and it is seen as some flaw in your character, that is a bad sign.
Use google to check out groups. A simple search of the group name plus the word cult or scam will tell you a lot.
Use common sense.