Here you have Dahon latch repair parts. It is serious as a bike opening up during the ride may lead to a serious injury. When you go to inspect the bike open up the page and try to identify with the seller what is missing. I would err on the side of caution especially when you lack experience. You may end up with a bike that you do not know how to fix and are afraid to ride. Best would be to identify a Dahon dealer nearby.