I am in the same dilemma like you my friend. My eye sight is a bit weak and when on a CG-125, you can't look far enough or Clear enough @ high speeds. I can drive in daytime easily, but on night time, it becomes a Nightmare for me to drive the bike.
I consulted with about 10 Electricians and 8 of them said you don't have to spend like 5k just for the HID Headlight. You can also do it in very less cost.
They said that i have to find the Geniune Headlight of CG-125 from older models. Models older than 2003 had GLASSY Headlights as compared to the New ones which have PLASTIC headlights. I am referring to the Internal Silver Plate and the outside mirror.
They said that all they have to do is to increase the current of Headlight and light will be just fine. But the new Plastic Light can't bear the HEAT Intensity of the Light Bulb and WILL melt down. So to avoid from that, you will have to look for a GLASSY light.
Obviously you can't find it in new condition. But you will be able to find one in Used condition.
In My Case, i am still unable to find one lol xD