The eBay policy is that the buyer should commit to buying the item by going through eBay checkout (but not necessarily pay). Both parties are then free to exchange contact details. The buyer inspects the item, and if it is not what the buyer expects, both parties agree to a cancellation.
https://www.ebay.co.uk/help/policies/member-behaviour-policies/membertomember-contact-policy?id=4262...
