I tend to go to Halfords or local small bike shop first (that don't stock big name brands) to seek equipment needed for the bike, then specialist shop.
I find this cheaper and the items reliable.
The Halfords youngsters are really good, if I have an issue, I bring my bike in, they tend to look at it, fiddle with a few things and let me go free of charge, at times they come outside, tell me what's up and don't expect anything.
Local bike dealers tend to be a little more sensitive, a bit more expectant. They are knowledgeable on parts and brands and differences, they tend to be more intrinsic abut the item, this includes slating ''lower'' shops beneath them. Also the cost of getting things done is a lot more.
And I feel, they don't always know more, they only know what they have, and that's what they talk about and comes across as narrow knowledge, viewpoint and a little square in a specialist store. The range of items is less than Halfords as more specific thus knowledge is less but they come across as knowing more...I also feel the individuals that shop in the specialist shop are not always knowing, a bit pretentious, buying high priced item because they don't tend to fiddle with their bike and fix a problem but buy there way out of it.