Easily $1 Billion PROFIT (not sales) per Year. Probably $3 Billion in sales. C-sinos in Las Vegas make$1.6 Billion:
https://www.seattletimes.com/nation-world/largest-nevada-c-sinos-profit-1-6b-during-fiscal-year-2017/
This store is more Profitable than Any C-sino, store, or even business, period, full stop. That store is More Profitable than Amazon, Microsoft, Apple, you name it. It is by far the most Profitable business of any kind on Earth. Bar none.
As for closing masses of stores, that's an easy one. On the mainland, Sears/Kmarts are obsolete stores that nobody cares about. They lose MONEY, BIG-TIME. Guam Kmart (and maybe USVI) is/are the exceptions. They are more Profitable than any other stores on Earth. So he's closing the non-Profitable stores to concentrate on the probably 1 Profitable one. I don't blame him. Close the others and pull in That Cool BILLION without lifting 1 finger. And he doesn't even have to compete with Amazon down there because I don't think Prime is really a thing in Guam, due to shipping Costs. Rich oligarchs, Billionaires, oil barons, princes, sheiks, etc., all travel to Guam Kmart. It's like the Saks 5th Avenue of The Pacific for some reason. Don't ask me why. I don't shop there. But Wealthy tycoons DO shop there. I don't question what works. And this works. If it ain't broke, don't fix it. I will bet you $1 Million that Guam isn't sold/closed in 2021, since you seem absolutely certain that one of those will happen.
Few Years old, but still valid:
https://www.wsj.com/articles/the-last-place-on-earth-where-everyone-still-loves-kmart-guam-1516118140
https://www.dontwasteyourmoney.com/guam-popular-kmart-world/
And Ed is putting zero effort into this store and it still rakes in Billions. If anyone even made the slightest effort, we would be in Trillions with a "T". Multi-Trillions. They make More Money in 1 Week than Bill Gates is worth! Lots of Money.