Upgrade Video card a lot, or a little plus RAM?

Thanks to everyone who responded to my previous post. I've narrowed down my upgrade options, and would like your input on which way to go. FYI: I live in Newfoundland, Canada, and I'll include the prices I will pay here. Anything I save by buying online (especially American) I will mostly lose in conversion to CDN dollars and shipping here.

Current System (details in sig)
Celeron D 2.8 GHz
512 MB DDR RAM
BFG GeForce 5200 (3Dmark 05 scores around 230-250)

Would like to upgrade graphics (AGP only) enough to get me through a year or so, at which point I'll get a complete new rig.

Should I.....
A) Upgrade to GeForce 6200 and add another 512 MB RAM? (cost: $160)

or

B) Upgrade to GeForce 6600 only? (cost: $200)

Thanks in advance, I look forward to your comments.

FlipprNL