It was you who suggested UBI should cover basic needs for a fair system. The simple fact is that the cost of meeting basic needs will vary by region. Now, London needs low skill low paid workers like everywhere else does. If the UBI doesnt allow those people to live locally to their jobs then you end up with ferrying workers in on masse like some post apocolyptic film. You end up with segregation, the haves and have nots. The have nots being shipped in like slaves. Total recall remake. Elysium. Thats the world you seem to be implying would exist with your method of implementation.