Check BH, if it exists and price is the same or lower buy from them,
If item doesn't exist(they are selective) check Amazon. I guess they have an agreement with Adorama that i saw a lot of Adorama products are listed there, so no need to check Adorama website. And the second reason is they can sell the stuff that BH doesn't sell. If the price is reasonable buy from Amazon.
If i think the price is not fair or cannot find what i'm exactly looking for, check ebay, consider longer shipping period, and if i find buy from there.
If there's still no result, glorious google is always there for me