When I worked next door to your Line Mtc office in LHR, we charged a customer 40 GBP per hour for a MECHANIC's services.
Some companies charge 18GBP for a 737 turnaround in Essex.
Your quote of 40 GBP to fix a PC, or another 40 if the ENGINEER does it wrong first time, or a similar figure for an hours labour for a TECHNICIAN to change the brake pads on your Ford Fiesta is indicative of our mentality in this country that those prices are OK but if I pay 180 GBP for a return flight to Florida then I expect a good meal and loads of alcohol or else i'll write to Anne Robinson irrespective of the standard of engineering performed on the A/C prior to departure. I'm sure you know that already but it is a good thread to start to vent one's spleen!!