If you are unsure about the Ebay sign-in page, if you enter your correct user name (this is public knowledge anyway),and a false or incorrect password, (very important). If it is the genuine Ebay page, ebay will tell you your information is incorrect. If it's a spoof sign in page, in my experience, the page is simply refreshed, so you can then delete it.
UPDATE The above is clearly not true in all cases. I have received a spoof email which was using the real ebay sign in page, https signin ebay etc. The implication being that the ebay site itself has been hacked into.