The company bought the three Burger Parks on May 1 from James W. Hinkle because Hinkle was moving out of the area, said Sutton, 33, of Hagerstown.
Hinkle said the sale was in the "seven-plus figure" range. He said he turned down two other offers, including one for "six figures" more, because he respected the way the Sutton family conducts business.
"They're locally owned, well-established and the family works very hard," Hinkle said. "These guys are very people-oriented."
Sutton also praised Hinkle.
"(Hinkle) built a really phenomenal business," Sutton said.
Hinkle said the deal gives Sutton ownership of the two restaurants in Hagerstown and the one in Inwood, W.Va. It also allows Sutton to use the Burger Park name with a 25-mile radius of Hagerstown and Inwood.
Sutton said he plans to expand into Martinsburg, W.Va., Chambersburg, Pa., and Greencastle, Pa.
Hinkle started the fast-food restaurant at 812 Frederick St. in February 1989, later opening two more drive-through only restaurants at 511 Northern Ave. and in Inwood, W.Va.
Sutton, his wife, mother and sister own Freddie's sub shops on Dual Highway, Park Lane and Oak Ridge Drive. No changes are planned at Freddie's, he said.
Hinkle said he particularly wanted to sell to someone who would take care of the employees, some of whom have been with the company since the restaurants opened.
"That was the hardest part about selling," he said.
Sutton Enterprises employs 72 people at the two restaurant chains.
Starting May 15, Burger Park's menu began including Freddie's steak and cheese, chicken Philadelphia and meatball subs, Sutton said. The subs are eight inches long, bigger than the half subs and smaller than the whole subs offered at Freddie's, he said.
The 99-cent burger will remain, but the french fries were upgraded to a bigger size at the same price, Sutton said.
Fried chicken will be added to Burger Park's menu in the fall, he said.
Staff Writer Brendan Kirby contributed to this story.