I need to change my car's cooling coil. Something is leaking after going through a few air con services, they conclude it's likely coming from cooling coil as the outer area doesn't show any leak. The air also starts to smell, so suspect of mold built up in cooling coil.

I'm likely going to buy my own parts, but would like to know what would be a reasonable fee for the installation + gas?
I'm looking for some recommendation, please share if you guys have any contact for a good price around KL/Selangor area.

Thanks.

That's typically the case, when they don't have enough experience, plus wanting to sell their own parts. It can be a dodgy industry.