Hello Eddie;
I'll give you some ideas from myself as a vendor involved in a newly opened mall in our town. The 50k sq. ft. building was a major furniture store until the business was sold and moved to a new location. One thing that was left behind were dozens of wooden "carpet display cases", about 7' tall, 5' wide, and 2' deep, open fronts with overhead lights. The building owner put adjustable shelving in these units and rented them for $45 / month. In addition to these, he constructed booths, plus put in rows of open gondola shelving that is rented out by the running foot.
The business opened the first of the month with about 50% of the space rented and the reminder is quickly filling up. I hadn't sold anything in a mall setting for over 20 years, and thought I was out of the business after selling my shop inventory at auction few years ago. But like most anyone involved in the trade I had leftover items that I wanted to get rid of, and decided to rent one of the $45 display units. It's probably just the novelty of a new business, but I've been truly impressed with sales over the past couple weeks since opening.
(To answer your question on sales per sq. ft.; so far mine have averaged about $30 / sq. ft. / day.)
