Yes, most of the reputable sources have raised their prices roughly the same amount. Where I got my 300mm F4 from, the price of that has gone from £779 to £995.
I did find one site which is hard to believe they're genuine. Fancy a 580 EX II flash for 169 euros? Postage free as well!
How about my 300mm lens for 569 euros? Unfortunately they don't list the 400mm F5.6, I'm sure if they did it would be around £600!
Further investigation shows the goods are in Russia. Dare I risk a go? Not likely!