Let's have a look at this "Standard" service in more detail then. For starters, does that £60 include VAT, or is the real price £72?
*Check and externally adjust hubs, headset and bottom bracket.
In reality - give wheels a check for sideways movement. If excessive, spend 2 minutes adjusting free play in hub bearings. If I found free play in my hubs, I would be spending an extra 15 minutes taking the ball bearings out to check for wear in them, the cones, and the hub itself. At least a clean up and regrease job. Headset, again 2 minutes to adjust out any free play, but why is it loose? Bike shop would no doubt tell you to replace at extra cost. Bottom bracket; any modern ones I have seen are non adjustable, so again check cranks for sideways movement and if excessive, or any roughness in operation - new BB at extra cost.
*Replace brake blocks/pads (if required).
In reality - a 10 second visual inspection, and if any sign of excessive wear spend 10 minutes max replacing them (at extra cost for the parts).
*Lubricate cables (replace if required).
In reality - operate brakes and gears to check for smooth and proper operation. If all good then run an oily cloth over the visible parts of the cable inners. If not, slacken off cables so the inners can be pulled out of the outers, and lubricate them. If still causing problems, replace cables (inners and outers, at full RRP).
*Lubricate chain and derailleurs.
In reality - spend 2 minutes back pedalling and applying oil to chain, then wiping off excess with a cloth. Point some oil in the direction of jockey wheel axles and derailleur pivot points.
*Check and tighten all nuts and bolts.
In reality - spend 2 minutes going round the bike with an allen key to make sure there are no loose fasteners.
*Test ride.
In reality - at best, take bike outside, ride 50 yards going through the gears and checking brakes; return to shop.
Total time spent - giving them the benefit of the doubt that they actually carry out all the above tasks, 15 minutes if they don't have to adjust hub cones and faff with cables; 30 or 40 max if they do (have to mess with cones and cables). Extra time (and cost?) if they have to replace anything.