@leader21 Yes, shipping costs are annoying - see also a FAQ “International shipping is too expensive” at the bottom of the project page. Hopefully, this will change in the future. I can also imagine this product will attract some copy-cats who will offer similar products - without shipping costs with Chinese Post
I agree the HDMI option has a less attractive price tag, but I won`t need it. I am more attracted by the battery option. Note, the base device already contains the charging unit.
EDIT: According to FAQ you can use any 3,7 Lipo battery. So, a 10Ah battery should also work