If you have determined that you don't need AWD, why is a 535xi one of the options? Much better to look at the 535i and buy proper winter tires for it. It handles and performs better than the xi, gets better mileage, and is cheaper.

Drive the 3 series and 5 series and decide which you like. Determine what the net trade value will be on the X5 after paying off the loan, and decide then if you can afford it.

__________________
2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue