I thought of many times to order stuff from J&C, Calumet and B&H, especially stuff I couldn't find here, but the cost of shipping was always above 50 US$, going up as high as 150 US$ for a 14"x17" enlarging mask!
I remember when I placed in the shopping cart only one roll of film and the shipping was something like 40-50 US$(I can't remember which store)!
So I have given up ordering from the US, even the UK is a gamble as they charge "over-seas" for crossing the Channel!