wow! talk about service!
Where I shop depends on what I'm getting. I got my 5-pin MHL adapter (for my "old" LG Spectrum) from monoprice.com. But then I got the 5-11 pin adapter from Amazon.
I got a few cheap cases from ebay before I even got my phone. Then once I had it, I bought a better case from a Verizon corporate store.
If I need any more accessories that I don't need to see first, I'll probably stick with Amazon (Prime). If I need to see it first, Verizon or Best Buy. Then I'll see if Amazon has it cheaper.