Thanks. How does that work then? Do they pay and then I post the saddle? I wouldn't be happy paying for something in advance in case the seller didn't send the item. Likewise I don't want to post the saddle without knowing it was definitely going to be paid for. So what's the safest option?
Check if PayPal offers an escrow option - this way you can get confirmation that the funds have cleared, but they are being held by PayPal pending confirmation by the buyer that s/he has received the saddle (or you posting proof of postage). This way you both have comfort.
If you PayPal, it will tell you when the funds have reached you. Make sure you transfer them into your bank account, and when you can see they have arrived, you can post. Just be sure to use recorded delivery, and take LOTS of photos of it before you send as there are some idiots around who will abuse the PayPal buyer protection. Photos are your comeback if someone tries it on.