To be honest, from what little I can see, I'm not liking it. Maybe it's just your photos, but I'm left with more questions than answers.
the date looks smallish, almost squished the 2 appears to be too far from the rim, the 9 and the 4 look to be too far apart and the 9 looks to be badly formed. But again, all of that could be the angle of the photograph...you need good pictures as soon as you get it to really tell, also is there some kind of stain from the top of the date running up to the T in Liberty? If so, this could be an attempt to wipe out the word REPLICA that I've seen on other mercury dimes...NGC has an example on their website if I am not mistaken. http://www.ngccoin.com/news/viewarticle.aspx?NewsletterNewsArticleID=867
After close examination of the 9 in the authentic NGC picture, I have concluded that it appears to be a fake. The 9 is a lot larger and more defined.
for comparison here is the date area of a graded example that I own: and an image of the obverse: I think the date area on the coin in the OP looks very different.
I agree 100%. One of those coins your eye immediately flags, then when you compare closely your mind catches up with what your eyes already told you.
While I could be wrong, this smells of an ebay transaction. If true, that probably isn't something to lose sleep over.
True but if the seller really wants to he can make it a real hassle. Perhaps he knows the coin is fake and was intending to sell it hoping the customer wouldn't notice.
I am getting to the point any kind of rare 20th century US coin I would want certified before I buy, especially on ebay. Heck, even goofy crap I buy I am sending back as fakes more and more. Ebay has started to accelerate downhill since they disbanded the anti coin fake department. Brilliant move Ebay, save a couple hundred k and risk losing thousands of buyers. I honestly cannot recommend ebay to anyone anymore unless I know they are knowledgable. It's just a Chinese fake fest, might as well go to alibaba.
The entire date looks rotated counterclockwise, the 4 doesn't look doubled, the last 1 (underdate) is way too prominent. I'm with the others -- I don't trust myself to authenticate these 100%, but this one screams "not right" to me.
I'm with the crowd. The 1 is in an incorrect position, and the 4 should have some lower doubling. Even with the really bad photos, this looks incorrect. For those that say that there is no way to collect US coins uncertified, I would totally disagree. The fact is that the US has not been producing coins so long that each die (or pair) is not decernable in one way or another. In this case, I hope that the OP did not make a costly mistake. There are plenty of great raw coins. I'm working on a RB large cent date set at the moment, and the majority of my acquisitions will likely be raw. Not because I want raw necessarily, but because not every coin has been graded. If you take the time to learn about the coin that you want to purchase, you should be able to make an educated assessment of the coin and buy accordingly.
I think the rim and the fonts seem to be unusually mushy, which is usually a sign of cast. These days, counterfeiters are getting too smart - they know how to read forums like this and improve on their art of counterfeiting to earn your hard earned dollar.