I have noticed this too.
I was thinking of buying the 'knock off' 666m replicas they used to sell. They were out of stock back in March. I phoned them and they said they should have new stock in May, but they didn't have them in May, or since.
I would think if it is just import duty problems they would have just upped the price
Maybe the Chinese manufacturer they used has been slapped with a law suit? Who knows?