You're out for a ride and get a puncture . No problem but you know there is a bike shop very close so you hobble to the shop . They say £5 for a tube £10 to do it for you . You only have £5 and have the stuff to DIY but would like to keep your DIY as you are far from home . Will they take a bank transfer . No . Then you ask to buy a new tube just incase your DIY fails and they say £6 It seems some shops , no matter how polite and friendly you are just want to be dicks .