Base price 35i is $52,500 and base price for 50i is $63,000.
Here are the options packages for each:
xDrive35i:
Premium (ZPP) - $1,750
Sport w/19″ tire package (ZSP) - $3,600
Cold Weather Package (ZCW) - $900
Rear Climate Package (ZRC) - $900
Premium Sound Package (ZPS) - $2,000
Active Ventilated Seat Package (ZAV) - $2,100
Technology Package (ZTP) - $2,000

xDrive50i:
Premium (ZPP) - $1,750
Sport w/19″ tire package (ZSP) - $3,100
Cold Weather Package (ZCW) - $900
Rear Climate Package (ZRC) - $900
Premium Sound Package (ZPS) - $2,000
Active Ventilated Seat Package (ZAV) - $1,100
Technology Package (ZTP) - Not available as vehicle already comes standard with Navigation

Stand Alone Options:
Running Boards - $300
HD Radio - $350
Heated Rear Seats - $350
Rear-View Camera - $400
Heated Front Seats - $500
Automatic Tailgate - $500
Satellite Radio - $595
Soft Close Doors - $600
BMW Assist w/Bluetooth - $750
Sport package wheel upgrade (20″) - $950
Comfort Access - $1,000
Nappa Leather - $1,000
Multi-contour Seats - $1,200
Heads-Up Display - $1,200
Active Steering - $1,400
Rear Seat Entertainment - $1,700
Navigation with RTTI - $1,900
Alcantara/Leather Combination - No cost
Metallic Paint - No cost