Don't buy from forums, but if you do hear are some things you should.

About a couple weeks ago, I bought a pipe on a forum, not going disclose any other information. Now this was a rare pipe a, Swiss pipe I think, and the price was around twenty bucks. Before I bought this pipe I thought "Its going to get here and I'm going smoke it until it cracks." Unfortunately it hasn't arrived, and I am twenty bucks poorer. Now I am not saying that the seller is a con-man or that the forum is a breeding ground of crooks.  In fact this post will be several steps that you should do before buying a pipe on a forum. So that you won't waste money on a product that probably won't come.

1. Look for the Seller's record, and ask around. So that you can get feedback from other forum members and the admins.
2. Demand pictures of said pipes, and ask about where they from, what pipe company made them, and what condition are they in. The seller should the answers these questions. 
3. Ask for the seller to use Paypal, if they are not. To ensure that you aren't giving away your credit card number to a processing company that has a shady reputation.
4. Immediately ask for the tracking number after said purchase, and do not let up.  So that you can verify for yourself and make everything less complicated, 
5. If you did everything from 1-4 and still haven't received the pipe then you need to make sure it has arrived and hasn't been picked up by someone else. If you did that and still no pipe make sure you didn't give the seller the wrong address or if you do have the tracking number then contact the shipping company and berate them until your pipe is delivered.

So with that I'll puff you later