eBay tried to force Paypal as the only payment method here in Oz but it was ruled unlawful. Now you have to list papal but can also list other payment methods as well. It's basically a big moneymaking exercise -- Paypal charges astronomical fees but has no accountability like a bank would.
As for your question, send via registered post with online tracking and signature confirmation. This will cover you as the seller against any unauthorised transaction dispute or item not received dispute. Keep your airway bill. If you're worried about SNAD, take lots of photos of the item prior to sending including in the box.
If the buyer returns an item due to SNAD (particularly if she claims the bag is fake and you know it isn't) get the postal worker to wait with you while you open the bag, use them as a witness in case the buyer has done a bait and switch.
Follow all these steps and you'll be covered! Good luck.