You really need to keep prices of wheels with tires (particularly OEM tires) separate from prices of wheels without tires. Sets that sell in the $350-700 range probably have most of their value in the tires, rather than the wheels.
Sets of OEM '91-93 wheels are usually less than mint. Good ones just have some scratches, not so good ones often have major curbing, chips, or gouges. Sets without tires or with bald tires or with mediocre non-OEM tires usually sell for $100-200 or so. If a set is truly mint, just like new, it might fetch slightly more than that, but I don't know how much more, since that would be pretty rare.