The item number you have posted shows a DVD player with, at present, only one bid - yours, and no 'buy' option. So I am not sure what you mean about the email & 'buy now'.
If you have received any type of prompt to buy in your regular email but not through ebay messages, then it may be a fake. Although I can't imagine anyone trying to cheat you over a 10 dollar item, unless a fake email was trying to get your financial information. Either way, the item number shows the truth about the ebay auction, and that is the one to believe.
I have not seen this email of which you speak, but if you get a request for payment outside of ebay, - don't do it. You will have no buyer protection, and it whilst sometimes sellers are just hoping to avoid paying ebay fees, too often it is a scammer who will take your money or worse.
Sometimes these fake emails even look genuine, ebay logo and all, but if you are getting a request for money, a promise of ebay protection, but it is not to be done through the ebay site, you can send the email to spoof@ebay.com and they will tell you if it is a fake.
Is any of that what you meant?:-D