BiDi SFP 1000BASE-BX Personalizado 1310nm-TX/1550nm-RX 10km

Ordering was easy and the product arrived really quickly however no mention was made of the import/duty tax that needed to be paid to the carrier before I could take possession of the goods.
I realised that there might be duty to be paid but had no idea how much until DHL emailed me. Although I got a print-out of this amount it wasn't in invoice form so not sure how to put it through my accounting system?
Is it possible for FS.com to inform us of the tax before we purchase the goods please.