500Nitro,

Freight is ~$300, import fee ~$400, duty 3% (I believe), and the net price of a Chapuis would be $3273 (2550 Euros), so OK $4100 total cost would be about it. It would be cheaper if you import 2 as the freight would be less per gun.
It is an hassle, but not terrible. It mostly involves a bunch of faxes and delays and yes, some expenses.

I have imported some guns and will do it again. As a matter of fact, I have 3 in the pipe.
You cannot beat low end DR prices in Europe, because of the volume and local economic conditions.
Importers are basically making 20 to 50% gross margin because the DR market is quite different here in the US. That's why you can undercut them.
I am not saying that an importer should not make money, just that you can bypass their margin if you spend some time and effort doing the same things they do.
You are right, though; I did overshoot a bit by using "fat".
The only thing you lose in the process is the local warranty, which would basically be zippo on a similarly priced used gun anyway.
I guess that another point is that IMHO it is a lot easier to import a DR than to modify a shotgun and it's probably safer to boot. Granted you won't have the satisfaction of completing such a project.
By all means, one should take a look at all the costs and understand the process before pulling the trigger.
I just know it has worked out pretty well for me.
WC

P.S> As a matter of fact, I did the initial draft for my house (2 storey only) but paid an engineering firm to do the blueprints