There was a placeholder on Amazon for the PS5 and it was priced at 499.99 Euros (around £445). It was removed quite quickly. I think Microsoft and Sony are waiting for someone to make the first move regarding officially releasing the price. Sony need to remember what happened to the PS3 when they priced that too high on launch and it didn't sell as well as they hoped.
There was another one on amazon that was listed with 2tb drive for £600. Pretty steep.
They do lose a load of cash on each console at the start, supposedly anyway. The parts inside the PS5 would cost the consumer way more if they were building a PC with equivalent specs.