Nikon d5100 upgrade help? d750 , d7200, mirrorless ?

[Travis Wallace]

I am a novice but I know I am limited by my current d5100 and I want more manual controls. I have 3 standard nikkor lenses including the dx 35/1.8, dx 18-105, fx 70-300.

I have seen and read about the d7100 and d7200 and I like the weather-sealing but I don't like that it is missing a swivel display like my 5100. The d750 has some swivel but would have to be an import because the US version is $2000. So which Nikon body should I get that will give me the best learning experience or should I sell everything and get something else (mirrorless, another brand,  etc)?

Max budget is $2000 and choice includes:

1) New Nikon body plus one (1) used quality glass for astronomy telescope (wife loves watching programs about space so it will be an easier sell  )

2) Completely new setup (different brand, mirrorless, etc)

Thanks

[spidermike]

I am a novice but I know I am limited by my current d5100

How are you limited? What are you missing or what do you think a different body will enable you to do that the 5100 cannot? The answers to that will help us guide you to a body that will be a genuine improvement.

[Travis Wallace]

I only have one control wheel that I have to choose from in manual mode.

[NancyP]

Does the 5-way button on the back (the one that says OK) control one of the parameters while in manual mode? I am not a Nikon user. Maybe check the manual again? I know that I have returned to my manual time and again to try some feature I hadn't used or had forgotten about.

You might be best served by also telling us what subjects you like shooting.

[LesPalenik]

For a minimal outlay, I would keep the 5100 with the 35mm/1.8 and get a used 7100 as a second body. You could put your existing 70-300mm lens on it, or from the savings, you could buy a sharper Nikon 70-200/F4 or Tamron 70-200/F2.8 which you could keep even if you later switch to a full frame.