I finally found someone selling these that will ship to the US.
We have confirm the item you are looking for Microsoft LUMIA 950 XL Battery.
If you need to order just inform and will send you invoice form money request from PAYPAL.
BATTERY BV-T4D –39,90 EURO
FREIGHT COST WITH HELLENIC POST REGISTERED TO USA-- 10,00 EURO
TOTAL COST 49,90 EURO
Delivery time after 4 weeks to you from your order confirmation
Kind regards
PDS Electronics,
Kremou 13-17, Kallithea,
PC 176 76, Athens, Greece
Tel. +30.210.9566.401
Fax +30.210.9566.144
Email
info@pds.com.gr