It depends on what you plan to do with it. The machine will be ok for games that have been out already for a few months, provided you get a decent video card, but it will not be too good for new games (though with a good video card, they'll still be playable). First off, never buy a refurb hard drive. Instead, spend an extra 5 or ten bucks to get a new western digital or hitachi drive with 8mb cache. I'd even recommend spending a few more bucks than that and get at least 120 gigs.
The memory you are getting is good. The nforce 2 mobos work faster if you fill both memory slots, so It's good that you are buying 2.
The case is nice, but you may want to buy a new power supply. Sometimes generic power supplies work fine, but sometimes they dont. I would recommend buying a brand name PSU like an antec. It may be expensive, but it's better than finding out your power supply fried your components.
It seems you are on a tight budget, and if so, the processor and mobo you chose is ok. but definitely stay away from the refurb Hard drive.
If you want some recommendations for a budget video card, I'd recommend an Nvidia geforce 5700 or ATI radeon 9600. These will range from $90 to $130. If you play games, these are a great value.