It is frustrating. I try to go local as much as possible but savings and inconsistencies are frustrating.
I remember in Camden I was browsing the area since I was new to London, was in need of a bike; saw a new & 2nd hand place and said I wanted a hardtail for commutes but with touring bits on as I tend to carry a lot of stuff. Dude was only interested in selling me a new fixie. I said I can't ride them but he said I would get used to it and there should be no other choice.
I got exactly what I wanted off gumtree a week or so later.
Yesterday, needed some new brake pads (disc) for gf's MTB; local cheapest pads are £18.
CRC £6. Email this morning saying dispatched. When service is like that I know I can send them back free if I just decide against it, it's hard to stay local.
On the other hand, I had a recent horrible experience with Paul's Cycles online. Avoid these if you can. The prices are tempting but after sales is non-existent.