Need Advice On 2nd RAM Stick

This is what I have now: Geil Value Series 184 Pin 512MB DDR PC-3200 @ 2.5-6-3-3

I bought this since it was pretty cheap ($80) and it was all I could afford at the moment for this rig. Plus, it got pretty nice reviews. Now that I got the money, I see the Corsair XMS Extreme Memory Speed Series 184 Pin 512MB DDR PC-3200 and I feel that I should've gotten that instead.

Well these are my possible options ordered from "most likely" to "least likely"
1) Buy another stick of Geil. ($88)
2) Buy a stick of Corsair ($123)
3) Keep the Geil and buy 2x Corsair. ($246)
4) RMA the Geil and buy 2x Corsair. ($158)
Any other possibities? Which is the best way to go?
I'm just wondering, too... Is it really worth it?

the best way is to have 2 stick of memory from the same maker with the same speed, I would get another stick of geil, I don't know about perfomance between corsair and geil but if they had similar perfomance I would pick cheaper,

Geil: http://www.newegg.com/app/ViewProductDesc.asp?description=20-144-305&depa=1
The blue heatspreader looks cool...

Corsair:
http://www.newegg.com/app/ViewProductDesc.asp?description=20-145-416&depa=1

They seem pretty similar, however Corsair seems to be talked about more than Geil (which seems to be unknown around here)

i still need help with this...

Geil isnt bad RAM at all, and mixing RAM types isnt to good of an idea...if i where you i'd get another stick of Geil.