It is just the start of all your problems. As soon as you start upgrading your system for Maya there is no end to it. It is hard to have a system that can keep up with the software.
Why don't you start with upgrading your memory ? Doesn't cost you to much and both your OS and Maya will love it.
When it comes to the Graphic card I wouldn't spent to much on it. I have a solid gaming card and a profesional card but there is not much of a difference between the both of them. The Quadro card seems to be more stable. But in the end I still don't know how to use them to speed up render time. That is likely still not possible.
When you use a lot of high grade textures you want to have a graphics card with a decent amount of memory. When it comes to rendering, it is youre processor that does the job.
The cheapest way is to delete history very often. It can make your system run very slowly if you didn't pay atention to it. LOL !
Don't pin me down on this, this is just my own experience.
I am not a pro either.
Good luck!