P4 vs C2D

Will a, say, 2.00gHz Core 2 Duo make a significant difference over a 2.4gHz P4 without overclocking? Relatively new to CPU upgrading, and I don't want to spend $200 for a tiny difference when that could go into my gfxcard fund.

hay what if I get a pentium D, and get a D/AGP mobo

success?

i don't need a 8800GTX, all i need is bf2142 running on medium. my 6600GT 256mb can nearly do that.