Somehow, I never saw this post(?). I called the office in Sosua and they told me that aduana told them that 5 is the maximum. On the chat in your link above, they told me 20 is the maximum. I'm going to order 5 and see how that goes.With a 3 minute research, it appears that you could get a quote right here: https://www.domex.do/gestionaduanal
Or call them and check: https://www.domex.do/