How high end must your system be...

Don't be suckered into the 'high price better system'. Read some of the 'audio critic' stuff as putting sanity into the hobby.

Gee, i just blew the cost of a nice new car on my new rig..
...and speaker cable: Hmmm $2.50 YES TWO DOLLARS and FIFTY cents. eBay MIL SPEC silver plated 12 guage Teflon insulation wire (From Grumman.. prolly for a F-22!)
Anyway i bought a LOT of this just to have around for those "wire moments" and decided to wire my Maggy 3.6 with it. @ $0.25 foot times 2.5ft stereo pair that's $2.50.. of course I can SPLURGE and biwire.. Whew!! That's five bucks.
And it sounds really super fine.
(On the other hand I bought a new Kimber 7 meter Hero for the pre to amp for $750.00)
Above all else.. you gotta use your ears... AND what's BETWEEN your ears.

While you are at Radio Shack picking up the zip cord Mapman suggested, also buy a set of their Auvio interconnects. Very nice sounding for under $20, compare favorably in my experience to wires from usual suspects that cost more.

Match - Like knownothing, I readily perceive an upgrade in cabling on my mid-fi second rig. The answer to your question is yes. If you are using OEM interconnects, by the way, spending $50-75 on a lower-grade name-brand ic will probably be the best $50-75 audio purchase you'll ever make. That first step up is dramatic.

I changed the interconnects and speaker cables in my midfi system that I have in my office and I can hear a difference. The system has captured power cables, so they remain. In all, this setup costs about $1,000 - $1,200, so I don't think a system has to be "high end" to hear differences in cabling.