Simple. The US dollar is currently strong against the euro. There are more ex-charter boats here on the market.
Before you get too excited, most prospective buyers don't want a boat set up for charter
The dollar to euro exchange rate can change at any time and there are other transaction fees
involved when you try to buy European stuff using dollars. Expect to loose up to and around 5% to bankers, exchange rates and wire fees
, unless you plan to board the plane with a suitcase full of dollars.... Which can also be problematic... when it gets confiscated.
It's really only cheaper, if you plan to buy a Euro boat and then use it over here.
I just noticed you're from Canada
.... Bring twice as many dollars.