He just happens to have exactly what you want
Gives you his email address
It is a good price
He gives you pictures which come from a google search or someone elses old for sale post
Wants money sent via paypal friends and family or bank transfer or money2india or other non returnable source.
You pay and never hear from them again.
There are lots of members here who have been trading parts for a while.
Look for the Gold trader status beneath their names.
Many established members are very trustworthy too.
Watch out for the new members that join just to answer wanted posts!