could somebody help me out on the benefits of expensive phono and speaker cables?

Here's some info to  sink your teeth into. Plenty of useful info from someone who does know what they are talking about.

http://www.roger-russell.com/wire/wire.htm#conditioner

You may already know the author is a known designer. At least you will have more perspective on your decision. 

Playing with audio, and navigating thru forums IS MADNESS!

Tablejockey,

Your linked article by Harry Marynard is very informative.

Harry describes the relationship between wire resistance, speakers’ varying impedance and the amplifier’s damping factor.  These issues were addressed in the posts by b4icu referenced by khaki above.

Athough b4icu excluded ribbon speakers from his reporting, I took his advice and connected four feet 0 AWG battery cable from a Pass Labs 250.5 (damping factor of only 150) and modified Magnapan MG IIIa’s.  Maggie’s have a difficult load ranging from 6 to 2 ohms.  The experiment was upgrading from 16 to 10 gauge wires tested previously.  The results were stunning.

The installed signal and neutral battery cable wires were separated by four inches to reduce the possibility of induction induced noise, see WiilyWonka’s post above.

Total cost, $65.

Given the modest cost and ease of installation, OP might start here and move on to IC’s.

Just remember, cables ARE tone controls. Certain cables don't, "Get out of the way of the music", like so many people claim.  They all add their own signature.  Some add more air, depth, width, etc., than others. You have to see what works best for your tastes. 

Don't get sucked into the hype of uber expensive cabling. Cables are the biggest racket in audio.