>Would someone spend $1k for one lens for their $500 D3200 >class camera? >Esp if in a year or two the lens will be useless?
The lenses don't become useless. A hobbyist with a DX body and lenses is really set for 10 years or more, as the body will literally last a lifetime. The shutter count limitation is an estimate based on testing, and can be exceeded if the camera is well cared for.
Even once a DX body does die, the DX lenses can be used on all of Nikon's FX cameras. The only difference is you're using only the center part of the sensor, but you'll still get excellent photographs.