Hi topraf ,
Thank you very much for your post and question.
ATUM as of now does not have any accounting sync or integration built. However, we have already started developing a massive export premium add-on that will be, when developed, ready to export for XERO and QuickBooks. Giving you an estimate of completion would be a wild guess, but not earlier than May 2019.
Before the end of this year there will be a widget in the ATUM dashboard that will give you the value of your inventory (according to the cost price) at any time you open the widget (no history yet, just live value). So if you need the value at 01.01.2019 you will only need to look at it that day.
Hope this helps.