canary wharf has lots of international banks & financial institutions right? quite near to london bridge.. if it's located at the heart of canary wharf, then fine i guess. but there is (or was) some cheap flats nearby canary wharf..so, be careful..
try search the exact location..maybe can use yell.com or other UK search engine. then, find out on the surrounding condos' rental.. if can get 1k pound per week, that's good.
but u have to consider ID, renovation, tax, agent and other associated costs as well.