Yesterday Google revealed that Nexus 6P will cost $500 in USA and €650 in Europe.
Nexus 5x prices are better for our wallets - its $380. European price of the 5X is not the best as Google Store Finland has put up the pricing info and the 16 GB model is €480. That's dangerously close to the kind of cash a Galaxy S6 32GB costs - £380 on Amazon UK (you can even find it for less), in euro the situation is pretty similar.
Nexus 6P may be worth it, but 5X is not much of an improvement over the previous Nexus 5.