umm i preordered it on 4th october and i got the 3$ off lol due to the amazons preorder price guarantee :) just received an email they are gonna process it :) didnt even knew that the price fluctuated down to 19$ while i preordered it :P thanks amazon !
What you're not noticing is that there are 2 versions, one is blue-ray only and the other is the combo, and neither has a link to the other. Search for "Karate Kid" and both will be listed. As far as I can tell all extras are available on both versions although this isn't true for all movies that have separate versions. Amazon should do a better job of letting their customers know when this happens as well as what the difference are.