I also buy more online than in local shops. There are few shops in my area now, as what were here have closed, and since I primarily fish warmwater or tidalwater, the few shops that remain cater more to trout anglers, so offer little to meet my needs.
As far as equipment goes, at this point in my life, there is little I need, so when I purchase something it's a "want" and I'll usually make such purchases based solely on the price regardless of where it may be found.
Tying materials I buy when I find a good deal, and frankly I have enough materials & hooks now that I could probably tie the rest of my life & never use all of what I already have. Plus, I buy "cheap" materials, because I don't have much need for expensive items such as dry fly capes, so what I use is easier to find from a variety of sources.