10 percent for cables ???

" What percentage of your house's worth do you spend on upgrading your Kitchen?"

Nice analogy, John. (O:

Many would consider that percentage far too high, including myself. I would say 5% would be a good maximum number; I have about 4% in my own system. Put your money into your major components, not your accessories. Wire and cable will not make your system sound better - anything in the signal path degrades the signal. Think of it more in terms of doing as little harm as possible. Buy from the inexpensive end of a well respected company if you are unable to audition - a good and experienced dealer can also give advice in this area, though beware if they talk more about the wire and cable than the major components of your system.

The Ten percent rule applies to the ratio of the population that gay and also it applies to the number alcoholics or drug addicted people in the population. I think that each counts i.e. such that a gay alcholic would be in the ten percent of both groups.
To answer your question, I agree that cable choices should be made on an indivdual basis. I have some very expensiv4e Cardas Gold reference 2M interconnects a few audience wires and a PC from audience but am just as happy with my power cable #3 from Audio Dynamics.
I also use the Blue Basic Power Cord. I can't recall from whom but I have a few.
I have 3 custom made one is a pure silver PC believe it or not, from the same guy that sells MAC.
I bought some of Suburu Gurus cords with exotic black return wires on the outside in a fishnet stocking over a clear plastic that is filled with sheilding ferrites in a salmon color. Those are not pleasing.
My speaker cables are single run with cardas jumpers wich are superb but took an eternity to burn in. These are the smallest Jena Labs braid offered "Jazz" still not cheap. My other systems use MAC speaker silver over copper. I have used Phoenix Gold from Carver Pro . Audioquest ? Mountains etc. My basic carver pro sounded better but I snapped off the termination a few times and one side got too short for me.
I have always been a contrarian,until the day I did a speaker cable shootout. The winner was the humble Phoenix Golds. I still have a hard time hearing anything really impressive from a power cable but the silver cord is very good with my CD player and really does sound cleaner with excellent transitions and airy treble. The ICs that I use are very varied and do color the sound . One of which is the aforementioned Cardas which which I find quite pleasant. They have the Big Tone as an old devotee said and are overly cloying in some rigs but I bought the to fix a very precise analytical system that required a number of tweaks. These cord are not sterile they are warm as a fireplace on Christmas Eve. My Homegrown silver lace on the otherhand are my phono cables my CD to preamp are Audience Au 24s and on and on. The one thing is that I often found myself doing all sorts of gymnastics to fix a new relative expensive Ic to sound good.
I found the only fix it is pulling them and admiring them entangled with others on my basement floor or trading them for something. The dealers want to buy your rejected cabling as much as you do which is mostly not on life pal. They are respected (recognized but not a buzz) at moment cabling but worse less than zero it's like it smells foul and they want nothing to do with them. So you trade em or sell em privately or to a used cable concern at a very big loss.
There it is, to sum it up, my system costs total of approx. 14K for my big rig with no cable if you add the cable the their cost may indeed be more than 10 percent. The road to Nirvana is paved with expensive cabling. It is a natural way cables evolve in a system.
If you know an audioiphool like myself tell me if he has no cable calamity in their closet and I will assert that this person is impersonating an audiophile and not a real one.
Be prepared to take a bath on resale but if you buy second hand here you will not be gambling much. Do yourself a favor get cables that work just right in your rig, don't change the rig to suit the cables.

I wouldn't focus on numbers. Buy cables that work well with your system within a budget you can afford and that sound good to you. Take advantage of a good dealer if one is available nearby, who may let you try out cables with a deposit (It would be a nice follow-up to buy from that dealer, of course). If you don't have one then try the Cable Company's lending library (again, requires a deposit). You may want to see if you can tell the differences between extremes, and whether or not those differences are ones worth the price you may have to pay. You may even find that you like the more affordable cable! Then again, you may not be able to live without those $3000 interconnects with the mystery boxes attached. I don't think you should be running zip cord in your system, but I also don't think you need to determine your investment by a percentage. Especially on an accessory where markup can run the gamut right up to the most ridiculous extremes. Per the previous post, buying used and reselling is a good alternative too.

10% is good maximum budget guideline - although you can spend a lot less and it will often be just fine. If you have spent more than this on all your cables and interconnects then you might have been better served by upgrading components /speakers/room acoustics instead.