Spare tire considerations
I highly recommend having a full size spare for the MDX. I was one of the first to get one. If anyone wants all the details do a search. The bottom line is that there are NO cheap 17" steel rims available and there are NO (at least there were none a while back) aftermarket alloys for the MDX 17x6.5 size. The closest alloy I could find was a 17x7 for ~$125.
Tim will sell the OEM rims for $200 including shipping. I put a Michelin Cross Terrain on it for $140 (tire, stems, mount, balance). Hence I paid a total of $340 for an OEM rim and tire. I echo TheWorm in that ~$350 is the max anyone should pay for an OEM rim/tire set.