If a supplier insist on Western Union, you could pay through it but hold the releasing of the money until your order arrived. The supplier can check if the money indeed has been sent --- but, cannot withdraw the money since its release must be okayed by you, which you will only do so until you receive your goods. If it is a scam, you can still recover the money, less the fee made to WU but much better than loosing the whole caboodle to the scammer.