upgrade for fs2004 or fsx?

Greetings all!
My present machine (Abit NF7/Athlon 2600/ATI9600/XP) is dying from some hardware disease or the other, and it is time for an upgrade. I can run fs9 with lowish/mid settings quite well in my area of interest (stick and rudder mainly in a Realair SF260: no heavies and not really interested in simulating large airports).
I can't decide whether to upgrade to FSX and spec the hardware with that in mind, or to go for a (presumably) cheaper system that would make FS9 really sing.
My present machine (Abit NF7/Athlon 2600/ATI9600/XP) is dying from some hardware disease or the other, and it is time for an upgrade. I can run fs9 with lowish/mid settings quite well in my area of interest (stick and rudder mainly in a Realair SF260: no heavies and not really interested in simulating large airports).
I can't decide whether to upgrade to FSX and spec the hardware with that in mind, or to go for a (presumably) cheaper system that would make FS9 really sing.