Core 2 Duo Vs. Athlon 64 Duo

Pending an income tax refund from Uncle Sam, I'm going to upgrade my cpu and motherboard (currently a Pentium 4 2.4).  I'm not interested in buying the fastest processor out there; I'm looking for the better bang for the buck - Right around $300 or so.  As it is so far, these are the two options that seem pretty common:

Intel:
Intel Core 2 Duo E4300 Allendale 1.8GHz 2M shared L2 Cache LGA 775 Processor - $169
ASUS P5N-E SLI LGA 775 - $140

AMD:
AMD Athlon 64 X2 3800+(65W) Windsor 2.0GHz 2 x 512KB L2 Cache Socket AM2 - $109
ASUS M2N4-SLI Socket AM2 NVIDIA nForce4 SLI ATX AMD Motherboard  - $89
Since this is the less expensive option, I would also add this:
G.SKILL 1GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) System Memory - $100

Are these good options?  I do not have wads of cash laying all over the place, so I'm upgrading my system a bit at a time. 

Yes, my video card is a bit out-dated, but it still works.  I'm planning on just upgrading the processor and motherboard now, and waiting until some DX 10 cards drop in price a bit before buying a new GPU.

So, are the AMD and Intel processors fairly comparable, then?  I'm leaning toward AMD because of cost, and I figure that if I need to update later on, then I can just get a new processor instead of replacing the whole mobo.

Like I said, those motherboards were just some common suggestions that I'd heard.  What are some better options for me?

Thanks for the help!

Yes, my video card is a bit out-dated, but it still works. I'm planning on just upgrading the processor and motherboard now, and waiting until some DX 10 cards drop in price a bit before buying a new GPU.

So, are the AMD and Intel processors fairly comparable, then? I'm leaning toward AMD because of cost, and I figure that if I need to update later on, then I can just get a new processor instead of replacing the whole mobo.

Like I said, those motherboards were just some common suggestions that I'd heard. What are some better options for me?

Thanks for the help!

Hortinerd

Yes, my video card is a bit out-dated, but it still works. I'm planning on just upgrading the processor and motherboard now, and waiting until some DX 10 cards drop in price a bit before buying a new GPU. Hortinerd

I think you missed the point. If you're using an AGP video card, it will NOT WORK with those new motherboards. The only way to use your current card if its AGP and update to AM2 or Core 2 Duo would be to get a hybrid mobo, and they are not very good, especially for overclocking. Or get another AGP board but that would be silly. This is why I was saying its hard to update one step at a time when everything is old, basically every interface you have will not be supported by new hardware. Socket 478 is dead, ddr1 isn't supported with ddr2 boards and AGP doesn't work in pci-e. So unless you're planning to have a dust collector until you get a new card, you'll have to get a card along with that other stuff.

The core 2 duo beats the AMD processor by a lot, but since you only have $300 to spend, I would go for the AMD package there and see if you can pick up an el cheapo PCI-E or even plain PCI video card to actually get the thing running until you can buy something better in the video department.

Yeah, with a move from your mobo to the lga 775 you have to upgrade more than that and the cpu. You need new ram, new video card, the new cpu, and possibly a new psu. The only hardware you can potential avoid having to buy again is the dvd/cd drives, mouse/keyboard, monitor/lcd, speakers, and maybe your hard drive.jfelisario

I think you missed the point. If you're using an AGP video card, it will NOT WORK with those new motherboards.... BeavermanA

My current card is, in fact, a PCI-E, so that's easier to work with.  I'm not a complete newbie to computer upgrades, just behind the times with what's "current" and what's not.

Crap. 

Turns out my computer, and my brain, really are getting old.  My video card is, in fact, AGP. 

In light of this fact, I'll probably be better off putting my money in savings for a month or two until, A) I save up enough for the processor, memory, motherboard and GPU; and B) some newer, less expensive DX 10 cards come out. 

What's the standard for a power supply these days; 500 watts?