eBay and Craigslist finds

so, i'm thinking about buying a bike from a newly started ebay seller with no feedback (no, not the gios).
is there any good tricks or advice to tell their reliability?

ask the a technical question about the bike that a cyclist would know the answer to but a street urchin would have no idea about.

eg. "hello the forks look like they might be columbus 531 tubing, are they?"

ask if it an be viewed before the end of the auction, you dont have to carry money and you can then gauge if they are genuine or not.

sorry if i missed something.