Need advice for upgrading PC!

[Eugi]

I did some research since my last thread, and because I am deathly afraid of wasting my money or buying something I can't use, I wanted to pose my question again with the additional information.

What I have:
1.70 GHz P4
768 SDRAM
GeForce3 Ti 200
SB Live! Audio
250W Power Supply
Windows XP Home SP1
Proprietary Dell Motherboard (can't find an actual brand/name)
Approximate PC age: 3 years

What I need:
A graphics and sound card upgrade that will allow me to play the latest titles (Half-Life 2/Doom3) with high graphic settings (I'm not particularly educated in graphics, but I want to say "At least Anti-Alisaing x2").

My means:
$225 BestBuy Giftcard that I want to use up completely
Cash. Roughly $200-$300. Can splurge for more if the deal is super sexy.


I've looked at statistics for different cards, but to be frank the different numbers are meaningless to me and it is my sad experience that higher (numbers) do not always mean better end result. For a rough guideline, I would like to stick with GeForce cards and am actively considering Audigy for a sound card. Of course, a GeForce means I will have to update my power supply. I have no idea as to what is the difference between the power supply brands (or if I will even be able to install one). I'm also on the lookout for a new case (I don't know any competent brands that provide middle-of-the-road solutions) as the person who put down-ward facing USB ports on my Dell case is truly evil. I realize this is quite a shopping list, however I appreciate all your help. Thank you in advance.

Oh, and attached is a picture of the slots I have on my motherboard (top black one occupied by the GeForce). I have trouble determining how to tell the different slots apart, but know that, depending on which one I have, it'll determine the cards I can get.

 

[turtile]

6800gt $280 (agp version)
Thermaltake 420w $40
Either a Audigy 2 or an Extreme Music X-fi $50-130

(you should consider selling your Best buy gift cards on Ebay)

 

[Kilew]

That pc is a dell you say? Well, you're a bit unlucky there as Dell use proprietary components, and the old motherboard won't fit into a new case. To play Doom 3 and Half-Life 2 on high settings and AA turned on, you're gonna need a processor and ram upgrade aswell. What all that means is you'll need a new:

Processor
Case
Motherboard
Graphics Card
Memory
Power Supply
(Windows Xp?)

Basically, you're looking at a new computer completely, but you can transfer your old CD/DVD ROM drive, hard drive, floppy drive from the old Dell case into the new one.

 

[Eugi]

So the slots in the picture are all AGP eh?

Well, I guess that settles it..

GeForce 6800 GT
Audigy 2
Thermaltake 420W

Hopefully that'll fit under a reasonable price at Best Buy >_< I'd sell the cards, but they are a gift, plus I'm not sure if I could get 1 for 1 value on e-bay (which is what I need)

Anyway, I hope the above set up will allow me to play HL2 and Doom3 with at least SOME graphic enchantments :O