eBay/gumtree confusion

Hi,I have responded to an ad on gumtree for a motorhome, which I am very interested in purchasing. The seller tells me he tried to list it as a classified ad on eBay but that it somehow got transferred to gumtree and does not appear on any eBay listings. He did, though, say that any sale must be handled by eBay and for this he would need details of my eBay ID (he has not said he needs my password) to register the 'buy it now' sale through eBay. I'm more than happy if this is the case but can't find any reference anywhere to this eBay/gumtree arrangement and how it actually works. Any confirmation/advice gratefully received.

---

Orignal From: eBay/gumtree confusion