You also have to consider that the D7200 is now, well old. A replacement for consumer grade cameras come out every two years or so, and suddenly you feel you have a "stone age" camera and you feel you "must" get rid of it. For that line of cameras at least.
You are presuming I do not feel a value in something I intend to keep for a while.
The D7200 does some things better than a D500
The point I was making is that anybody with a D300/D300s who has not tried the improved performance of the D7000, then the further significantly improved D7100, then the moderately improved D7200 has missed the point that if they do not consider an upgrade they have missed out on the
significantly improved images that are easily available.
Some are happy with at best good quality 16x12 prints at no higher than 400 ISO, with modest dynamic range and hardly quicker the 1 fps shooting 14 bit. For many photographers this is enough.
The D7200 provides at least 15% more image resolution (compared to 300s) with every lens owned, generally 2-3 stops greater DR, 30x24 print potential at 1600 ISO, better colour, higher fps and better AF. A lot of photographers consider this a worthwhile upgrade.
How often one upgrades is personal choice - I do not still drive my first car which was not new in 1973. If care is taken to find good new discounts (in UK some dealers have "one day deals"), keep equipment in good condition together with the box etc upgrading can be relatively painless.
The "pro-DX" D300 had a pretty good "longevity". You yourself went through a D7000, a D7100 and a D7200 after the D300,
Yes - but its image quality cannot come close to cameras like the D7200.
--
Leonard Shepherd
You can buy kit. The rest is mainly down to you.
The more you practice, as with a musical instrument, the better you are likely to become.