Btw, even if you DO want to put in Hi-OCtane, DO NOT go for "Half and Half". Put jus 1 or 1.5 Liters of Hi-Octane and fill the rest of the tank up with normal Petrol.
As long as you use good quality petrol, your bike will be fine.
CG125 is VERY sensitive to bad fuel. So i'd say CHOOSE only ONE petrol pump which offers the best oil (look for user reviews as well ... say, PSO pump in Model Town, or Shell pump just before Batti Chowk) ... and then keep using its normal petrol. I am sure you won't be disappointed.
In my whole life, i have NEVER used more than three petrol pumps, and mostly have been using ONLY ONE. The Shell Pump at Larri Adda, which is not there anymore because of the construction. So now i have to go all the way to Batti Chowk to get it filled, which is like 8 kms away from my house. When i am in my institute, i used to use PSO Pump at Model Town Roundabout, and its quality of fuel was pretty good too. Actually very good.
Other than that, i have never taken a risk of checking out other fuel stations.