It simply comes down to this: 
(1)If you are one of those who upgrade pretty frequently, then getting a 128mb card a waste of time. You will have upgraded already by the time games can use that extra memory.
(2)If you plan on using the card for a while, then I might could see the extra VRAM.  Otherwise, you are better off saving your cash for later.
Here are a few links to help your decision:
 
http://forums.anandtech.com/messageview.cfm?catid=31&threadid=692845&highli ght_key=y&keyword1=128mb
 http://forums.anandtech.com/messagev...keyword1=128mb  
http://www.digit-life.com/articles/1...rds/index.html 
(Good article with benchmarks)
Alot of people have the same outlook as you: "It's only $35, why not get for the future." And I agree....But....all that RAM does you no good certainly now, and the core speed of this card could be behind by the time games can use the RAM. 
Example: Think of a V3 with 128mb trying to play MOH - all the RAM does you no good if the core is slow.  If you are thinking that this card will play games in 2 years ultra fast because of the RAM, then you are mistaken.  Yeah, sure..the games in 2 years will probably be able to use all of the 128mb of onboard RAM, but the card itself will be sooooooo slow.
I would have gotten the 128mb version too, but then I found out that it appears to not be able to O/C as much as the 64mb card.
[This message has been edited by BlueWeasel (edited February 01, 2002).]