Last time I checked, it is cheaper to buy from Maco Direct than from Fotoimpex (Adox's own in-house shop) - applicable only if you buy a lot. But I guess you'll have to check the total price with your post code. I tend to buy my film stocks from Maco, like there RPX 25 and 400, and retro 80s too.
Silvermax 100 is a lovely film. I only used one roll of it so far with HC-110, and like the output. Shame it's not (&_will not be, according to Adox site,) available in 120. I wish Adox could offer it and other films in 25/50/100 feet long roll to minimise the cost. Oh well!
Bests,
Ashfaque