I was talking about CPU, not PSU...
I got that, my point was that for any kind of rack-mount hardware it may be better to have good PSU and decent CPU and RAM so this device can be relied upon. I had some trouble mounting about ten of such a switches in a single rack since I got manage to connect these external cheap PSUs in a respective PDU.
By the way, these MT switches have plenty of room inside their cases to place internal PSU inside.
Adding more RAM won't play that much with the price, too. This clearly a way to prevent converting switches into routers, not the thing MT can be proud of.