Re:- by going to Maplin.
Everytime I go to my local Maplin I get accosted by spotty teen floor staff at the entrance asking whether 'they can help?'. It's probably the most annoying shopping experience I've endured trying to actually get into a shop while wanting to purchase the thing I need immediately. Knowing their mark up is based on the emergency factor anyway, they should preclude having to run that annoying gauntlet to get the bits people need.