I've only just seen this but just to give my two cents...
You were quoted sixty pounds and then told seventy-five, that's a joke: both the amount and them changing price. Them also doing work on your bike that you didn't ask them too would grind my gears. You never really need to remove the centre stand at all, but agree it does get stiff. Just simply lye down on the ground and spray water or brake cleaner or degreaser into the middle of the mounting bolt on either side whilst working the stand with your hand up and down and it will eventually free and work as normal. Never try to remove it at home, the things a pain in the arse to fit.
Getting a track pump from halfords or alike with a PSI gauge on and topping the tyres up once a week is usually enough. Make sure you do it before a ride when the tyres are cold.
The job doesn't take twenty-four hours, that's just them being lazy. It takes an hour or two at most. Here's what you'll need for next time:
brake piston seal kitbrake fluid DOT 4brake bleedersealey brake caliper toolThen the standard socket (14 mm) and an allen key to get the bottom holding bolts out. A baby seringe from a pharmacy to reverse bleed the caliper usually speeds up the job to get the air out the system before bleeding conventionally.
You wont need to replace the pistons again in the time that you own the bike if you clean them regualrly, don't be fooled into thinking its normal to buy them every time.
Remember to take the calliper off the bike (that doesn't mean take the brake hose off) and clean the brake every nown and again. It will gunk up inside because of how its located, but that doesn't mean it needs rebuilding. Simply take the pads out, pump the pistons a little and spray the brake cleaner and clean with a toothbrush (get a pack of four for £1 from anywhere so you've got spares), push back in with sealey tool and then put brake pads back in with copper grease on the back, put pins in then pump rear brake pedal and jobs done.
You only need to rebuild the caliper (minus pistons) every year or two.
Save yourself money and always rebuild the rear on your own: simply take the caliper off the bike, remove the pads and then pump the pistons out with a block of wood or something in the middle so they come out evenly. Then use a pair of caliper piston pliers to wriggle them free.
The front brake calipers is where you need a shop since you usually have to do one side then the other and that means tkaing them off, rebuild attaching to bike bleeding and then again on the other side: or compressed air if you've got it.