City breaks get a reputation for being expensive because people book the famous five and nothing else. Step one city sideways and the same trip costs half.
Lisbon still delivers more for the money than almost anywhere in Western Europe — tiled streets, seafood, viewpoints and a room rate that has not caught up to its popularity.
Mexico City is the food capital most travelers have not visited yet. Museums, parks, markets, and restaurants that would carry a two-hour wait anywhere else.
Budapest, Porto and Montreal round out the list. All walkable, all served by reasonable flights, all with room inventory deep enough that member pricing bites hard.
The rule that matters: pick the city for the price, not the postcard, and book four nights instead of three. The fourth night is almost always the cheapest one, and it is the night you stop rushing.