It's impossible to comment unless you tell us what you want to use the PC for.
Gamers, for example, need hi-spec vdeo cards and fast processor (as do people who mainly use their computers for video-editing), whereas such things are just a waste of money for someone who only wants to do a bit of word-processing and web browsing.
Similarly, if you intend to download loads of videos (and actually store them on your PC, rather than on an external device) you'll need a really big hard drive but, again, that would be a waste of money if you're only needing to store a few documents and emails on the computer.