They look a little expensive to me but I am not in need of a set. No connection to me I just spotted them on one of my regular E-bay trawls. They have been around on E-Bay for some time.
You should inspect the photos of those carbs carefully as the bowls and tops are not a matching pair and one of them has been drilled out at the base to accept a bolt to replace stripped threads inside the bowl. I think the price is eye-watering and then you'll have to fork out even more money to restore them.
Have you tried Andy King? His stock is always changing and you may get lucky.