Ok - for around $200 + 25 shipping and handling and change plus mounting you can get items to build your spare on-line or at your dealer. Discounted pricing at getBMWparts.com
Collision Catalog - 2001 - BMW - 330XI front suspension, wheels, wheel, spare 330i, 330xi $57.28 PN 36116750007
OEM Catalog TIRE 125/80D17 99M C $148.80 PN 36122150029
Tires are about a week on order. So for about $250-275 peace of mind and a new set up.