D600 vs D700 for the next 7-10 years: which is the better investment?

In seven years time you will be lucky if a digital body is worth 75% of what you paid for it and in 10 years time may be no more than 10%.

Whether any software as we know it will still be around in 10 years is unknown, but not much supports the original D1 these days.

Seven years from now you are talking the equivalent of D100 technology, long since surpassed. Cameras like this still take pictures, but  with nothing like the quality of anything on the market now

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Leonard Shepherd
Many problems turn out to be a lack of intimate knowledge of complex modern camera equipment.