From what I understand on the Dutch forums, they say you should stick to English words.com and Dutch words.nl
hypotheek/mortgage is big for advertisers obviously.
Google keywords suggests less than 100 searches a month.
You may want to register on a dutch domainersforum like sitedeals.nl and ask there(english ok).
Other possibility is selling it to a Dutch bank/financial institution or to the person who owns hypotheekcalculator.nl and krediet.nl(nice site/credit.nl)