Strangely enough after this upgrade the urge dissatisfaction returns and you soon forget how much better the Naim was than the NAD - and so you climb aboard the upgrade roundabout and keep improving your amps.
Finally, years later out of curiosity you dig out your NAD integrated and compare it to your new ££££ Naim six pack/twelve box combo and your jaw drops and it's not funny.
At the last show I went to some manufacturers were driving £10k+ speakers off MacBooks and iPhones via Wi-Fi. Have a look for yourself the next time you go.
As for the Magico's, as long they have enough power to feed them without clipping I don't think they particularly care about the cost of the amplifier. The Magico's cost is not related to the cost of the amplification required to drive them. Not in any engineering way at any rate. How could it be?
Sure you can spend more on amps if you want, that's your choice - just don't kid yourself you're getting significantly better sound just because everyone says so and every dealer implies it.
One day I intend to explore the world of Valve amplification myself - some certainly sound different from transistors (less earthbound to my ears) and I can hear it.