The VR 70-200 is a Fx lens and with the large image circle, at 200mm is it a little soft but on a Dx image circle there would be no softness. It is a rugged well made lens that really works well as a portrait lens as well as general purpose telephoto. It is a good match for a D7000, focuses fast and sure.
If it is used on gymnastics, how far form the athlete, what light levels and type of light? There nothing faster in a zoom so if it is too dark for decent exposure at 5000 ISO, you will either need a camera with better noise control. By carefully selecting the lowest shutter speed that can freeze the action you can optimize the exposure triad. I often see people just setting the shutter at 1/2000 or whatever and complain about noise, but there is not much action a human body can do that requires that high, particularly if you are far from the action.
Another trick if you need higher shutter is to intentionally expose in RAW 1-2 stops underexposed. The sensor in the D7000 has a linear noise curve, sometimes called ISO Invariant which means an under exposed image boosted in post will have the same noise as if exposed normally. That would allow a higher shutter speed for freezing the action but low enough ISO so there is acceptable noise under exposed 2-3 stops by raising the shutter speed 2-3 stops allowing the image to be 2-3 stops darker than the final image would be printed. In Lightroom or other RAW rendering program, just boost exposure 2-3 stops and you will end up with non-blurred image with the same noise as if you exposed normally.
I have that lens and use it on a D7000, D800 Fx and Z6 Fx and it works well. For price you mentioned I would expect to be in perfect condition. One that has been used as much as mine would only fetch $600 or so. Mine has been all over the world and shot probably 300,000 frame and never let me down.
The Tamron G2 is a good lens also, but new it is about 1200euro. The earlier versions might not be upgradable to be compatible with newer camera.