That is a good question about the quality level at the difference price points.
If memory serves, Katzkin offers a couple "levels" that correspond to how much of the seat is covered in real leather. The higher level with more leather is called "Upgraded Content".
Note that this info is difficult to find on the Katzkin Site but you can configure a custom Katzkin kit on a Site like autoseatskins.com and see all the details.
Just the prices you listed don't tell us what that coverage is, but for sure, you would want something written in the quote to specifically spell out the leather coverage for the given price.
As I mentioned earlier in the thread, I think there are some "stock" kits that they build ahead and offer for a lower price (like the ones I bought on eBay), then there are the full custom kits that cost significantly more (but you get exactly what you want). I expect the Mopar versions are the stock kit variety as they don't show any sign of the custom features (different insert colors, piping, contrast stitching, etc.).
FYI - A year in and my Katzkin is showing no wear and no wrinkles. It took about a month after I installed it for the warmth of the sun to smooth everything out.