Switch to silver for a treble boost?

My system isn't resolving enough to warrant an upmarket PC (and I'm a bit of a fence-sitter there too).

I'm quite happy with the sound of my CD player and amp via a pair of Grado h'phones; it's via the speakers that the system seems to lack treble sparkle, and I guess a $100 pair of speaker cables is cheaper than changing the speakers (which I'm otherwise happy with for bass and mids).

This really begs the question, what speakers are you using?

B&W DM602's (large standmounts). The bottom line is that for my system I know these speakers are ok, but thanks to years of playing in bands my upper frequency hearing isn't what it used to be. The Grado h'phones are on the bright side, which compensates somewhat.
I'd rather tweak a little extra top end by using different cables, rather than having to change speakers or using the tone controls on the amp.

Get the silver and try it out. If you don't like it, you can always resell and not lose too much, if anything at all.

There is little doubt that as a rule thick copper cable will tilt the music energy to the bass and mids overwhelming the treble. I am uncertain about what surgical silver "core" wire is exactly. My first experiment would be thin gauge copper Zip cord. The thinner copper cables are IMHO much better balanced than those whales intended for subwoofers.
If you are committed to silver then I would look into these.
Try the Signal Cable silvers or the Home Grown which comes in various thicknesses and prices. I must tell you that a real silver cable of that length will cost a lot more than $100 even used. You can generally find a lot of bargains for used cable here. It seems that trying and not liking, then selling a cable is a common practice. The fact that it wasn't for one person's taste is irrelevant you may love it.