I looked into this as it sounded wrong, and I think there's different information blended into one.
There are Dutch universities with 40% of international intake (that's the same or even less here than the % at King's or Imperial College), but that's not the % across the country, which is not as high as some other European countries (UK is one of the highest).
Also, there are scholarships open to international students, just as there are in other countries, but they are overwhelmingly not fully-funded - Maastricht offers a whole 24 (!) per year for international students, for example. The NL Scholarship referred to is a part-funded one for the first year. Otherwise as an international student you pay the usual 8-20k p/a you would anywhere for a bachelors or masters, with the higher rate for outside of the EEA.