As stated in other postings, I witnessed one involving Telescopes.

The telescope was a Meade 14 inch LX200 reflector. It was listed as new.

The seller was in The Peoples Republic of China.

The retail price of the telescope was ~$6500 but he would sell it for $450.

I was to send the money via Western Union and he would send me the 'scope. Promising a full refund if I wasn't satisfied.

He insisted that I trust him.

Well, I insisted he trust me, (I had more feedback than he did) and told him to send me the telescope, first, and after I received it I would send the money.

He lost all interest in the sale. Oh well

Perhaps all others should use the same approach if the validity of the seller is in question (i.e. no link to paypal or requiring money to be sent out of the country via Western Union or others).