3...d5!? is coming!
My guess--but my readers can tell me if I am wrong--is that most amateurs who play 3. Nf3 are doing so because they wish to avoid the Nimzo. They probably don't expect to face a QGD after black starts with Nf6 and e6, so you will have them stumped. And, since few opening books cover the Ragozin variation, you might get them out of book very quickly. Of course, they could have figured out these move order issues, in which case the game will be a hard fight--but that is ok as well.
For my analysis of move orders click this link to my QGD-Ragozin-Nimzo Move Order Analysis.