Originally Posted by Homebrew01

The more expensive wheel will feel insulted to share the bike with a less expensive wheel, and will thus have increased resistance. However, studies have shown that the cheaper wheel, in an effort to feel accepted and prove it's worth, will have less resistance than normal, and will likely make up for the increased resistance of the expensive wheel.
If both wheels are expensive, but of different brands, then both may have increased resistance due to having to cooperate with one of "them".