Write to the company asking if they make a 220 volt version. If so, then they might sell you a new motor you can fit yourself.
At almost $400 dollars for the unit it'd be worth it.
Is it possible to get a dedicated 110 volt line in a European home (that would be hot/neutral/earth)? The 220 volt lines for low-amp stuff (15/20) here in the USA are hot/hot/earth.
Are you sure it won't work with 50HZ? I doubt that such a high-power device uses a synchronous motor which depends on line frequency. And even if it is affected, I don't think it will slow down the dryer that much. Getting a dedicated 110V line in Europe is pretty much impossible I guess, with maybe some exceptions. Where exactly do you plan on going? I don't know for other countries, but in Austria used spin dryers are available almost for free.