NEVER NEVER NEVER pay for a high ticket item on ebay with a Money Order or Wire Transfer. I speak from painful personal experience, I got suckered into a sweet deal on an S2. I sent off $1400 and 2 months later I'm still waiting for the camera. The auction turned out to be a hoax.
Any reputable dealer on eBay will accept PayPal or similar, and that way the buyer has some protection if the seller defaults. Western Union have strong warnings on their website that Money Orders should be used only to send cash to family members or close friends that you trust completely.