amazing machines can be had in the 600-800 that give you hardware already outclassing xbox dumb. If your going to make the investment at all why half ass it? For that much more you open the world up, you can have any major title plus all the random shit people have put online, free mmos, games in beta, sales on steam, and you dodge out of the way of some crazy things that happen on consoles that nobody can do anything about (dont skyrim saves on ps3 crash out at some point?). Patches for games with problems can be instantly available. Mods for games can make something as old as morrowind still relevant and beautiful today. In fact most games you have played on a console look absolutely nothing like the pc version.
PLUS, i really dont get the type of person that plays these games and not for a minute wants to see what they look like on the inside. Do you know want to open the tes editor once and poke around? Download the latest versions of UDK or Unity? Or check out the latest open sourced code from older games? Your xbox dumb going to give you that?
Really if games dont matter to you that much why do you bother at all? I just dont get it. If you cant afford just THAT little bit more shouldn't you really be better off working a second job instead of sitting around just mindlessly wasting time?