i will repeat what others have said – i too know many people in lakewood who not only didn’t demand a down payment, but they didn’t demand any money from their parents and/or in-laws. some got some money and some didn’t.
and for those who say college is leading somewhere and learning in kollel isn’t. i don’t know, but most people i know who’ve learned in kollel, end up having jobs in which there learning was in preparation for – such as being rabbeim, ravs of communities, mashgiachim, or even “just” to be a talmid chochom who is also an accountant, computer programmer, etc.