Is this worth it? Rebuilding an iMac to a screen

I’m currently looking for a 27” iMac to rebuild it as a screen since they’re very cheap and they have the resolution I want (and the design).

If the screen looks like this, it’s most likely the graphics card and not the display itself right? The seller says it’s flickering sometimes, does this mean the screen is also broken or is this all related to the graphics card?