It states they welcome fine wine and champagne on board in reasonable amounts, how expensive does it have to be in order to bring it on board?

They don't care - it can be the cheapest thing you can find, or the most expensive. Doesn't matter!

They don't know. The people loading your luggage onto the ship don't bother to check there handy "list of the worlds fine wines" before putting your luggage onto the ship.

They are probably more concerned with how much you bring. A couple of bottles is no problem. A case may be pushing it. It depends on their mood. If you try to bring the wine to the dinning room, they will charge you a "corkage fee" of $15 to consume it in the dinning room. UNLESS you bring bottles of stuff they sell on the ship and then they can't be sure if you got it in a gift basket or not... So if you bring wine, try to bring one from the wine list.

Jim,

That was a most excellent get to the point post in my humble opinion