Originally posted by philbaum One can't always tell what dreams are impossible - unless you try them.
That's certainly true - and great art have been created because someone refused to believe it was impossible.
Differences in performance in cameras may or may not be a factor whether something is "impossible" or not. By all means, if you believe (or can verify) that it DOES make a difference in your case, then buy the right camera. But if it does not make a difference, find another way to achieve your goal.
I tend to find with all equipment incremental benefits stop being significant beyond a certain price point and individual skill/experience/usage becomes a more significant factor. When I started riding a bicycle, I went from zero to an A group rider on a ten year old bike rescued from someone's garage that I rebuilt. These days I am a C group rider on a $4k bicycle, and I doubt buying a $12k bicycle will significantly improve my performance. Yes, I can get back to the A group (and they keep asking me when I will return) but it will have nothing to do with the bicycle. Similarly we invested over $100k on our home theatre, but with my ears I can barely hear above 12kHz.
There is no real reason for me to buy new cameras or upgrade to a better model - there hasn't been for many years. I do it because well, there is a certain joy from buying a higher performance model, and frankly I can't take my money to the grave so I may as well spend it. But I am realistic enough to understand that in my case it will do nothing to my photography, regardless of the supposed improvement in specs.