It’s been six months since the Bel-Air estate owned by Osama bin Laden’s brother, Ibrahim bin Laden, was listed for $28 million. And so far, despite its prime location — within walking distance from the famed Hotel Bel-Air — there have been no takers. The seven-bedroom, five-bathroom abandoned estate received a price cut of $2 million last week on January 26, the listing shows. Situated on over...