Anyone would want a better product even if you get your savings a little later, Its up to Jonathan5 to decide isn it? Thought taxes were like 3% in the states. My mistake if their slightly higher.
We'll im sure my worst enemey's HP ain't dying on him, mabye it is i haven't talk to him in a while...lol
as time is progressing all i see ECS keeping up with other companies a step down a notch, im not a fan of ecs, im getting the Gigabtye 780G motherboard for my HTPC setup.
Video Card - It's hard to pick this out because it mainly depends on your preferences. Are you wanting higher settings or would you settle for middle quality settings? A very good ATI HD3850 can be had for around ~$170 or a lower end nVidia 8600GT (I would right to get the best card that you can afford. Just look at the charts that I listed earlier.
Case - The one that you picked out. $29.99/plus a case fan
If you can possibly use the one you have now, just make sure that the motherboard would fit. It would save you $29.99+the fan+shipping=~$50
PSU - I'm not hundred percent what to recommend here. A good PSU would probably be around ~$50<, but remember not to skimp on this component.
Something to go by would be a ePower 500w $46.99 Newegg.com - ePOWER ZU-500W ATX12V Ver. 2.0 500W Power Supply 115/230 V UL, CE, FCC, TUV - Retail (This would the lowest I would go.)
Look at the 12v Rails: If it's a single look for at least 28 amps or if it's dual look for at least 18+ amps