I wonder if one of the reasons for slowness in the market for Levinson amps, aside from the situation on Agon, is growing recognition that there are "two Levinsons" -- the equipment Mark Levinson actually designed himself, and the stuff designed and sold after he sold the company. In many cases, it takes a lot of effort to sort out which is which, and most folks probably don't want to invest the effort. And it's been so long since he had any association with the name that I suspect virtually all the cache is gone.
Levinson wasn't the engineer who designed the components; that was Tom Colangelo, who went on with Levinson to form Cello. Levinson isn't a EE, he's a musician / recording engineer sort of guy.
Levinson the man moved on from Mark Levinson the company before 1984, so the brand name has been without its name sake for a very long time.