Just out of curiosity Majland, do you have the shorty levers from an eBay site like the one's you can see in Pepsi's post? I have them on mine & Ive noticed that where the cable runs from the lever into the adjuster the cable is not central in the hole when pulled in & out. You can feel it more so when turning the adjuster as the slot in it catches on the cable when it is facing to the front. Since dicovering this I now like to keep the area where the cable & adjuster rub well greased.

And with regard to the original "What do you get charged for parts" The dealer I bought the bike from gives a 10% discount on everything I get from him. Which is better than a kick in the teeth.