My last string purchase was from Just Strings, mainly because I needed a few things I couldn't find at any of the local shops, some single high E strings, and a set of C6 lapsteel strings, and a set of ground wound bass guitars strings .   They were quick and have a really good selection.  If it's available,  I'll usually try to buy local.
All of the guitars that I purchased new were bought from smaller local shops,  either here, or in a city that I used to visit for work.  I've bought other stuff from GC/MF and Sweetwater like mics and such but not guitars.