[Solved] Upgrade processor or graphics card first (specific question)?

Hi, I am about to upgrade my 4 year old PC, but I don't have the money to upgrade both the processor and the graphics card. My system has the following specs:

-Intel 945GCL motherboard with Intel P4 3.0 GHz
-1 GB DDR2 667 MHz RAM
-GeForce 7300 GT 512 MB gfx card
-80 GB + 120 GB SATA HDDs
-LG 19" LCD monitor (1440X900 resolution)
-Windows XP SP2
-Local power supply (will have to be upgraded)

Now, the best thing would to be to upgrade both CPU+RAM and the GPU, but I don't have the money to do that. Is there any point in upgrading the GPU+power supply only? Will it make a meaningful increase in performance for my games? I was thinking of an HD4850 or a GTS250 graphics card.

If I go for the other option - upgrading the CPU+RAM - the problem is that if I do not upgrade the motherboard as well, I won't be able to use DDR3 RAM. I don't see any point in spending money on something that is already close to being obsolete.

Your help will be really appreciated

Thanks for that link. It is good to know that my motherboard is still in the game

I know that there will be some bottlenecks, but what would be interesting to know would be as to how much of a bottleneck will there be. If it isn't too much, meaning that HD4850 or GTS250 would be able to give decent performance, like running Crysis on high details at 1440X900 resolution, I would be happy to wait until I have the money to upgrade my mobo+CPU+RAM.

The advantage of this is that my HD4850 will still be pretty solid 6 months later when I do have a better CPU. If I choose to upgrade the motherboard+CPU+RAM first instead, the increase in performance in graphics will be negligible IMO.

But this will only work if there will be a significant improvement in graphics by just upgrading the gfx card, which will give me good-very good graphics for 6 months when I will be able to upgrade the CPU as well. After all, graphics card get "obsolete" much faster than CPUs, as far as gaming is concerned. I would like other people's suggestions in this regard.

OTOH ,,if,,your mobo can take the upgrades,why not wait and do it all at once,because the $$ on some items will go down,OR,you could purchase as funds become available,and at "on sale" prices until you have all the parts..