Don't kid yourself... the cost of ownership for an X5 is going to be relatively high.
The MDX combines luxury (not bmw... but not toyota) with good reliability. Cost of ownership could be much less than the BMW. That generation of MDX's have plastic timing chains which need to be replaced at 100,000 miles IIRC, so watch out for that repair bill.
The 4Runner will be the most reliable and have the lowest cost of ownership. You could get a clean 2004 or 2005 Limited 4.7L V8 4x4. The interior.... well its a Toyota. Don't get your hopes up.
Source: Have had (in the family) a 2001 MDX for 10 years, 3 X5's, and a bunch of other bmw's. I'm also going to be in the market for a 4Runner possibly this summer.
Last edited by Andy2108; 01-24-2013 at 12:52 PM.