Reminds me YET again of wonderful advice I got in a business law class in college - here is the rule followed by his reasoning.... (and not sure **I** agree 100% with them.... but if you at least STOP and consider the issue, you are a long ways from helping yourself NOT to make a bad decision
1). NEVER enter into a General Partnership - Each partner is fully responsible for the actions of the other (idiot) parther. If your partner makes a bad business decision YOU could lose YOUR house, car, boat, and EGADS!!! YOUR EGG!!
2). NEVER adopt your spouse's child(ren). In the eyes of the law, there is no distinction between a natural and an adopted child. If the marriage later collapses, you could end up paying child support for a kid that is not "yours".
and here it the one relevant to this topic...
3). NEVER, EVER purchase something if someone approaches you - phone, mail or in person. DO YOUR RESEARCH YOURSELF BEFORE MAKING any agreement.