PC power supply

I was looking at a new PC for photo and video editing. I saw somewhere on one of the threads that you need to make sure you have a large enough power supply to run the video graphics card in your machine.

I was looking at a PC from Costco and it had a 350W power supply.

I decided to check the graphics card and went to the manufacturers website to see what the recommended PSU was for that graphics card and it said at least a 400W power supply.

Is this common? Why would a company build a PC and purposely underpower the components it put in the original package?

Am I looking at this correctly?

Ron