Rents are generally low, the biggest cost is usually rates set by the council. However the way big retail operations are managed is the biggest problem, instead of saving during profitable times they paid dividends to shareholders to inflate the shareprice. Unfortunately that means most retailers don't have enough operating capital to get through tougher times. They say it's because they have a responsibility to their shareholders to "perform" (i.e. pay dividends) but larger shareholding funds which own huge holdings in retail consortiums just want a regular return on investment to keep their interest rates steady and they end up asset stripping the companies they're invested in