Probably the two photography websites are B&H Photo and Adorama...but there are many others. But as far as finding them much cheaper than sites like Amazon...don't count on it. There is a reason that the price is the same everywhere. It is the manufacturer controlling the price - and authorized sale prices - as a condition of being in its authorized dealer network which also includes factory warranty coverage. Lower prices are typically through dealers NOT part of the authorized dealer network, lacking warranty coverage, and generally referred to as gray market. Same exact produce off the same factory line but not obtained your country's factory distributor supply line to its authorized dealers who actually creates the warranty - which differs from county to country. I noticed that when I played exchange rates and purchased a lens from Canada and the accompanying warranty was significantly more generous that that provided through Sony USA. One thing to be aware of with Amazon and others that have aggregated shops, be careful who is "sold by." While Amazon may be an authorized dealer, sold by XYZ Camera Store may not be.
Manufacturer's price control actually does a disservice to their authorized dealers where they can't even follow a business plan. If they want to have a sale of X% everything in the store...they can't, and you see the fine print disclaimer excluding a list of brands. Similar happened to me at Home Depot where, as a veteran I get 10% discount on everything until I went to buy a Honda lawnmower...and Honda prohibited the discount. As a consumer, it has really changed the game on purchases with prices the same everywhere, it doesn't matter where you buy it and with States aggressively enforcing tax collection it eliminated the 6.5% "savings" at B&H. (Personally, I think States have it backwards - but that is a whole different issue). As a consumer, price control and tax together neutralizes local vs online decision, and comes down to what secondary benefits apply that sweeten the deal. For me, it comes down to a variety of veteran benefits and some cash back credit cards or store programs, such as Best Buy's rewards program.