Memory/RAM for an Inspiron XPS

I'm trying to upgrade my Inspiron XPS (generation 1) from 1gb to 2gbs of RAM. Twice now on ebay I've bought ram that didn't fit. The first time I made the mistake of buying DDR2 instead of DDR.. and this time i'm not sure what my mistake was. The memory that is currently in my computer is labeled:

PC3200S-30330
512MB DDR 400MHz CL3
HYMD56-4M64A6-D43 AA

The two sticks I just bought read:
1GB 2RX8 PC2-5300S-555-12
HYMP512S64CP8-Y5 AB-C 0729

If I buy the ram directly from Dell its going to cost over $200. I'm trying to be cheap about it and go through ebay.
What numbers do I need to look for?

 

You need DDR not DDR2, I like NewEgg for buying. You need a 200 pin SODIMM DDR(1) and you should be good to go!

 

agreed, here is the memory which I can guarantee will work in your system:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145562

Here is a link with all of the laptop memory on newegg, with a 1gb capacity which will fit in you laptop:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2000260381%201309221122%201309121113&bop=And&Order=PRICE

As mentioned in my first link, I highly recommend OCZ, Corsair and Kingston, all of the other brands just are not up to par.

K-TRON

 

Thanks for the fast replies. The reason I was interested in upgrading my memory in the first place was I got the impression it wouldn't be too expensive. Unfortunately I was looking to spend a total of around $40 for both sticks. 50-60 for 1gb is a little out of my price range right now. But now thanks to you guys I can keep my eyes peeled on ebay.

K-Tron, what is it that you like better about OCZ, Cosair, and Kingston? Do they perform better?
Also, do you know why DDRII is roughly have the price of DDR?
I did find two 1gb sticks on ebay within my price range that look right to me.. I probably won't win them but its worth a bid.

EDIT: Also, how important is the speed of the memory? I'm interested for gaming purposes. I've upgraded to literally the only video card I could for this computer (ATI Mobility 9800 Raedon 256mb) and with 1gb of ram the games I play still run at low FPS at times. (I Mostly play World of Warcraft, which runs at around 25fps normally but drops to around 5-10 when I'm in crowded areas with lots of character models to load)

 

ddr memory is so much more expensive, because no new notebooks on the market use it. The demand is for ddr2 laptop memory, because every new notebook uses ddr2 memory. Its ridiculously cheap, because the companies are selling extremely large quantities of it.
OCZ, corsair and Kingston manufacture high quality memory cards, and they have become known for it. Most of the other manufacturers use lower quality memory chips in order to get lower prices. Dont be fooled. Cheap memory has more errors in it and it becomes corrupt much quicker than good performance memory.

DDR memory is expensive, I bought 2Gb of DDR PC3200 corsair memory for my Voodoo laptop in May of last year for $120 per Gb.
Its sad, because I put 4gb of memory in my Dell for $40.

K-TRON