I started out with Photoshop Elements 9 and upgraded to 10. Then I bought a stand-alone version of Lightroom. Eventually I upgraded again to the PCC and Lightroom CC offer. There are differences between Elements and Photoshop CC.
If you edit NEF's, there are limitations in Elements--some tools and adjustments simply aren't there. I'm looking at Elements 10 now and don't see a way to get over to ACR (Adobe Camera RAW) once I am in the editing section of Elements. In PCC, I can go back and forth whenever I want. Possibly newer versions of Elements have more features.
Even though I have both PCC and Lightroom CC, I don't use Lightroom CC. Lightroom excels with organizing and cataloging which is a feature I don't use. Hopefully others can tell you the benefits of that. But the biggest thing for me is all the editing tools of Lightroom are available in PCC when I go to Adobe Camera RAW.
Once you learn the editing features of Lightroom, Photoshop CC offers many more things you simply can't do in LR. If you haven't yet learned a lot of the features that Elements offers, you might want to upgrade to a newer version of Elements. You will have some NEF editing capabilities plus some editing capabilities of Photoshop. Once you've used the program enough and feel it is lacking, that might tell you it's time to move onto one or both of the full versions.
I was fine with Elements but didn't know what I was missing until I went with PCC. Just about the only time I open Elements is to crop a screen shot because it loads faster on my computer than PCC.
Files I've edited in PCC can be opened in Elements, but first they have to be converted from 16-bit to 8-bit...so for me there really isn't any point in doing so.