Percentage of cable cost

Buconero, I too was naysayer, an open minded skeptic if you will regarding expensive cables...until I tried them. Actually it pisses me off that they DO make a difference...even power cords! I really, really... wanted to draw the line, cut some corners somewhere...but if you have decent separates, they can and will benefit from better cables. As for the % in question, list price of course, if I had paid list, 19%. If I had not got short speaker cables for monoblocks and kept my gear low and in the center it could of easily gone up another 5% of total MSRP. I don't think there is a formula that works for all but it seems like anyone with an optimized system ends up being at 15% on the low side and 25% or more on the high side. Tmsorosk...Don't feel bad I would easily be close to your % had I not used as short as possible runs wherever possible and I'm toying with "interviewing" some $$$ power cords.

If I was still on the upgrade path 10% cost on cables is a safe bet. Before going higher optimize the room, a lot of what cables will add can be negated by reflections and standing waves. If unsure about major system changes in the near future stay on the conservative side as your needs may change. That being said once ALL system bottlenecks are removed or addressed that % can be higher and yield benefits as fruitful as any other big upgrade IMO. In my case of around 19% is also including power conditioning. My speakers, amps, and preamp will likely be the same for the next 10 years so this will be it for this system.