i dont mind live in a shoebox as i am from somewhere very exp on living, as long as in a decent area and enuff for a couple is fine!
how much space would you consider to be adequate for a couple?
what are you seeking - 1bed, 1bed + den, etc?
if you're coming from a place where the cost of living is expensive, then 500 SF (if you use metric, ~ 45 square meters) maybe considered a castle to you, while for many in North America it would be small (ie. shoebox).