did you send it insured?

if not then unfortunatly std first class is only covered up to £30 anyway so if you did refund and then had to claim off reoyal mail you would only get £30 back anyways.

what postage service was offered in your listing? if it says std first class then you should really offer insurance at extra cost to the buyer, if its over 30 and it gets lost and they didnt pay the insurance then the problem is theirs not yours in that situation, but as said if ever i sell anythnig on ebay i always send it by courier.