IBM wrote:
I would not keep it , as you said you may be able to pay of your D750 with the cash in selling that d7100 , but the money will be less every month and year you keep it , and most of that cash must be in the lens that your selling with it , cause the 7100 body alone will only bring in 4 or $500 at the very most , and if you ever feel you need a DX body get a used D3200 and one normal 36mm lens or the 18-105 nikon vr
Lens .
My Pentax FF {purchased 1984} and Pentax APS-C {purchased 2015} share lenses.