I contacted Iwata, as their W400 has the same M16x1.5 female fitting for the cup as the gun I have. My gun is a rather cheap one though so far it's good enough for me (no point in having an expensive gun when you're not doing a lot more painting than what I'm planning). Guess what the Iwata cup would cost me? About $100 (at the current dollar/SEK rate). At the same time, a new gun of the kind I have would be half that. Right now I am looking at three used Iwata cups being auctioned separately (currently at $5 each). If I don't score one of those, I discovered today that a 15mm LDPE tube (which I can get for free) cut to a manageable length could work as a paint container. I would have to refill more often, but it could still be used as opposed to just being discarded.
*edit to add: it's not that I couldn't afford a new gun like it, I just don't like the idea of scrapping it because of a f****d up cup

[This message has been edited by PerKr (edited 02-04-2011).]