Using wire transfer is a sure way to lose your money. Always try to use a company that accepts credit cards or paypal so if something goes wrong you have options of recovering your funds...
Also, not all companies that use just wire transfers are scammers. Some are indeed legit.. The best way to cover yourself is to check out the company before you buy..You can do a simple google search by just typing their name into search and see what comes up...Also check with the scam alert sites such as the 'ripoff report, firetrust, dogpus, 419 legal, guru buster, and site like that. Normally if you check with those sites you will find a company listed if they are scammers....