They will drop the price in Europe soon enough...maybe wait until September or a little later. We should expect the MRP to drop from £425 to either £349 or even £299, although I get the feeling that they will just introduce the new 80Gb version with Motorstorm and reduce the price to £399.
Prediction (June 12th 2017)
Permanent pricedrop for both PS4 Slim and PS4 Pro in October.
PS4 Slim $249 (October 2017)
PS4 Pro $349 (October 2017)