Bushy, Here in the USA good serviceable 404s on original German or English Mausers are very pricey
I would not expect you could touch one for less than about $2500 unless there was something wrong with it. For higher grade guns, the price could go WAY up.
But that's just my guess.

It's probably going to be less money for a CZ.
I see you don't really want a CZ. Why is that? (if you don't mine my asking?)

You can make a 404 out of several other actions, but the bottom metal has to be changed, and that necessitates a new stock too. So you have to make a semi-custom, or custom rifle to get one that way.
I was told that Ruger did a few a while back on #1s and on M-77s, but I don't know if that's true or not.
One other option is to buy a rifle in 458 Lott and rebarrel it. I think you will still have to widen the magazine a bit, and probably have to re-work the feed lips a bit too. But that is less work than making a whole new rifle from the action up.