I have a relatively low-end system so for increased video rendering performance where would $100 best go towards? A better CPU, video card, or a chunk of memory?

The system basics:

AMD Sempron 2400+ slightly overclocked and stable from 1.667 to 2.0 GHz (I hate the way AMR puts a numerical label on a processor that doesn't reflect the clock speed)

768 megs of DDR 400 memory

nvidia MX-4000 128 megs DDR memory



I'm leaning towards a better video card but if the CPU is a data bottleneck...that is what I'm wondering.

BTW my apologies for not being active in the GTR league but my nightowl tendencies makes it nearly impossible to be fully awake at 6:30 AM. If we raced at around noontime or at 2:00 AM...