Why is there any debate on this? We all know headphones sound better with a good amp and dac. So everyone should obviously buy one. If you cannot afford them buy the headphones you want and grab the amp/dac in a future purchase. But to say that you can ink by without one, you're seriously missing out.
I understand what you are saying, I know that sound will be improved with an amp. But as you say, I can't afford all. What I want to know is if the M50's will be still be decent without one, and if there are any worth buying open cans which can also do without amping.
Later I will buy an amp, I just don't know when. And my portable player has a 37x2 mW amp which I think is better than many.