If you have a 32 bit OS, it can only use up to 3GB RAM (technically, from what I understand, it uses 3.5GB but only 3GB is useable) so even upgrading to 4GB RAM would show no difference whatsoever and you would simply be paying for something that you wouldn't be able to use.
It would be advisable to save the money and just use it either on the graphics card/processor or alternatively save it for a future build.
I do know what you mean about having a very limited budget. You can try and see if you can source computer parts from friends or family friends who no longer need their own computer and are happy to either give it away or for a small cost, but check whether they actually have the item that would prove to be useful for you.
You sound relatively happy with the computer you have and just want to make sure you can get the most out of it to make it a little bit better. You can, if you want to get the maximum from the computer, try overclocking the processor. However that can shorten the life of the processor and the motherboard, so its only if you have a back up computer or a new build in progress and you want to see exactly how fast the computer can go.
It would be advisable to save the money and just use it either on the graphics card/processor or alternatively save it for a future build.
I do know what you mean about having a very limited budget. You can try and see if you can source computer parts from friends or family friends who no longer need their own computer and are happy to either give it away or for a small cost, but check whether they actually have the item that would prove to be useful for you.
You sound relatively happy with the computer you have and just want to make sure you can get the most out of it to make it a little bit better. You can, if you want to get the maximum from the computer, try overclocking the processor. However that can shorten the life of the processor and the motherboard, so its only if you have a back up computer or a new build in progress and you want to see exactly how fast the computer can go.