This was just posted a few days ago in a similar thread, and is definitely worth reading:
http://www.roger-russell.com/wire/wire.htm#introduction
The gist of it is that provided you buy decent quality copper with sufficient gauge for the length of cable run, then there's no reason to spend big $$ on speaker wire.
I know my recent switch to $15/metre Kordz cable made no difference from the cheap 18AWG stuff I'd been using, and all my gear is "entry-level" too.
http://www.roger-russell.com/wire/wire.htm#introduction
The gist of it is that provided you buy decent quality copper with sufficient gauge for the length of cable run, then there's no reason to spend big $$ on speaker wire.
I know my recent switch to $15/metre Kordz cable made no difference from the cheap 18AWG stuff I'd been using, and all my gear is "entry-level" too.