Commercial property owner and operator The Georgetown Co. has purchased One Washington Mall near Boston City Hall for $56.73 million.

The New York firm bought the 16-story office building at a far higher price than seller Saracen Properties and a partner paid in 2006.

That’s at least partially thanks to office supply giant Staples, which recently built a new two-story, flagship store in the former home of Newbury Comics at One Washington. The Framingham-based retailer occupies about half of the property’s first floor, shared by a Planet Fitness gym, and takes up the entire second floor as well.

Plus, the firm has leased more than 45,000 square feet of space to new tenants and increased the building’s occupancy to upwards of 80 percent. When Saracen and joint venture partner AEW Capital Management bought the 156,000-square-foot property for $33.5 million in 2006, the property was just 60 percent leased and had not had a new tenant move-in in more than 24 months, according to Saracen’s website. Saracen then oversaw a $3 million capital improvement program for the building, including new elevators and a completely renovated main lobby.