1- don't ever send Western Union /MoneyGram /or cheque money transfer... only Credit Card or Bank Transfer cos you can claim and return the money if you didn't receive your goods...
2-the seller must be company. he should then use the company email not yahoo or hotmail
3-get the company number and call them. ask for the customer service and check on the sales person, return policy, refunding, company services and history...
4-if you are getting a much better price from your seller that means something is worng.. don't believe it.