There seems to be a difference between the available Store Credit of yours with the site currency you had picked previously. Would you like to:
XBOX Live (Microsoft) VideoGame USD $83.68
XBOX Live (Microsoft) VideoGame USD $66.95
XBOX Live (Microsoft) VideoGame USD $45.64
XBOX Live (Microsoft) VideoGame USD $30.72
XBOX Live (Microsoft) VideoGame USD $50.2
XBOX Live (Microsoft) VideoGame USD $56.29
XBOX Live (Microsoft) VideoGame USD $44.12
XBOX Live (Microsoft) VideoGame USD $42.59