@ Etienne, it is human nature to worry about what others did or didn't do (in this instance 'pay'), but you should only worry about yourself. Two years ago, the graduating MBA class at Harvard University were given a survey questionnaire with 2 options and were asked to specify which they would prefer:
(1) to get a job paying $200,000 per year, whilst the rest of your class secure jobs paying $250,000
(2) secure a job paying a starting salary of $120,000, whilst your classmates get jobs on $80,000
The result: the majority opted for (2) They were more concerned with relative position and rankings than absolute income. The moral of this story: forget what someone else paid for a DSLR, and focus on whether in the future a new DSLR would suit your needs, then save the necessary cash to get what you desire.
Good points, but it's an emotional thing as much as it is an extra $500. Plus, I don't really need the 5DIII, I just want it. My 5DII is still a great camera, but I am readily tempted by shiny new toys.
If my 5DII breaks, then I will need to get a new camera. In the meantime I'll just wait for a really good deal, or the next round of upgrades.