In my case, I tend to use ICs that synergise best with my system needs and ratio% will inevitably be distorted. Also, I rarely buy my ICs brand new (indicated below) and I bought most of my existing ICs from friends.
Some examples ...
A) Meridian 206 Delta Sigma CDP to Cyrus preamp uses Kimber Kable Silver Streak IC ;
The KK Silver Streak, WBT, IC = $NZ400.
Meridian cdp (2nd hand, and modified) = $NZ1500.
Ratio is therefore 27 %.
B) QED MB45 custom modded headphone amp, with uprated external PSU and regulation - used in the tape loop of preamp. Since its a loop configuration, I am using 2 pairs of half meter ICs ;
2 pairs of AudioQuest/Truth Emeralds x3 ICs = $NZ 360 total (secondhand - 6 mths old when I bought them).
QED MB45 with customised parts and PSU = $NZ 280 (secondhand).
Ratio is about 130% (!!).
C) Denon TU600 tuner, also modified, and IC used is AQ Lapis x3 ;
AQ Lapis IC = $NZ200 (secondhand - 6 mths old when I bought these). Denon tuner = $NZ500
Ratio is about 40%