BleepingComputer.com: i need some ram

i have and old dell latitude cpx
model no. ppx it says it is a refurbish computer as i know but it has original parts, the ram is 125mb, and i would like to put more in it but the only thing that i found is 255mb of ram i have to put 2 of this cards and they are expensive as i can't non belive, if i get a good offer i will be paying 50 bucks for 2 of this cards and they will not give me even the whole gygabyte. i open the case yesterday i saw that the ram card the computer has is not dell but is toshyba card, that gave me the idea that this cards can be swap around computers, so the question is.....
can i use ram from other brands to get better resoults?
the card that i found on the computer reads toshiba16mx64sdram pc 100-222-620 assy in usa.
i have also seen ram made from the company belkyn that says that can be use on laptops and desktops. they average 19.00 us dollas for a 1 gygabyte card, can one of this cards be use on the old notebook? i am learning about computers and i need the wisdom of the most experiance on this. thank you very much

Memory is a little more complicated that that
Your computer is very old. When it was new, it was shipped with 32 mb of memory. Maximum amount you can install is 2 modules of 256mb for a total of 512mb of 144-pin SDRAM PC133
For approx. $80
Not really worth it, I'm afraid