It looks like both the 830 and the 735 will be available in Portugal starting 3rd of October and the pricing is pretty bad for the 830.
The 735 will be sold for 250€ unlocked and the 830 will be sold for 400€ also unlocked.
Looking at both smartphones specs I really can't see what is justifing the 150€ price diference, it looks like the 830 will basically be dead on arrival no one will buy such a weak smartphone spec wise for such a high price, I have no ideia what Microsoft is thinking.