Wrong translation. The correct translation of the phrase implies the imperative mood.

src/oscar/locale/ru_RU/LC_MESSAGES/django.po

 #: apps/offer/conditions.py:269
 #, python-format
 msgid "Spend %(value)s more from %(range)s"
-msgstr "Потрачено %(value)s больше из %(range)s"
+msgstr "Потратьте на %(value)s больше из %(range)s"
 
 #: apps/offer/reports.py:22 apps/voucher/abstract_models.py:122
 #: apps/voucher/reports.py:21