DIY Landlord - Replacing Aircond Sensor Cost

Got a call today from my tenant who is a student at a nearby college. He mentioned the air conditioner in my unit in USJ broke down.  


Called one of my air cond repairman contacts who was nearby to take a look at it. Root cause was the air cond sensor. He billed me RM 120. I met my KPI to fix all repairs within 3 days. 


Just out of curiosity I did a check to see what was the cost of a sensor. Amazingly these items can now be found in eCommerce sites like Lazada and Shopee. Probably cost of the parts around RM30 (includes postage). Well, we're paying people for their experience, so workmanship I guess is quite fair for RM90.