Most schools, if not all, have payment terms that are available for students who cannot afford to pay in cash. Don't be scared to ask for this, it is normal practice among educational institutions to provide assistance to their students and future students. You can also look for Amity International School in Amsterdam for your kids.
Also, ask if they also have any type of other student assistance programs like scholarships and school jobs which can both aid in paying for the tuition.
Last but not the least; remember to ask about the teacher-student ratio in a class. Learning a language is a very delicate matter, it is important for students to be able to converse with their teachers for a long time. With this, the teacher can personally know the English proficiency of the student and be able to evaluate them individually and pair you with students that are of the same level. An ideal class would be one teacher per five students. If it is more than that, any teacher will not be able to teach an individual student long enough for them to really learn.
Remember, going to an English school is not a 100% guarantee you will learn the language; you have to practice speaking it with other people outside the school every day for you to really master it. Practice makes perfect!
Looking for good English in Amsterdam, Philippines? Make sure you check the school's references and look for student testimonials. Double-checking the accreditation of the English school will also ensure the quality of the education you will be paying for.