What does a €400k Algarve property really cost with all taxes?

Plan for roughly €425–435k all-in at purchase: IMT (progressive, ~€18–22k at this level), stamp duty (0.8%), notary/registration and legal review. Then the running costs: annual IMI, possible AIMI, and — the part Norwegian buyers forget — the property enters your Norwegian wealth-tax base and must be reported from year one. The purchase price is the headline; the structure is what you live with.