Try Radio Shack...they have a Monster version for about $99, then their own brand for about $12.99. Just make sure what you need is the DVI-I, and not regular DVI. DVI-I won't fit into regular DVI.

I have an lcd monitor with a vga input and a gf4 with a dvi output. I'm doing a second monitor thang, and I was wondering if there's any signal loss with a dvi-a>vga cable when using longer (5m) ...