Hi EWill,
Just in case you haven’t read it yet I would start with the tutorial post here which has all the basic information, steps, and guidelines you will need to make the best possible choices … and exclude the worst ones. I suspected you may not have read it yet because the guidelines there would have eliminated the #3 and #4 options on your list and of course your budget would have eliminated the others.
I wouldn’t pay much attention to Black Friday sales (or any other “special sales” that have major discounts) because better manufacturers and retailers have good quality and value options available every day of the year and don’t need to use the “fake sales” that are so common in the mainstream industry (see post #5 here) to create a false sense of urgency or sense of loss that can often lead to poor purchase decisions.
Your budget is certainly enough to buy a good quality mattress and I would just follow the steps in the tutorial post one by one. The foundation thread here also has some good options that are low cost and combine a bedframe and foundation and have storage space underneath them.
I’m not sure how far away you are from the closest options on the Los Angeles list but I would suggest calling the ones that interest you the most and that are in reasonable driving distance to talk with them about your budget, the materials you prefer, and what they have on their floor that is worth testing (and to make sure that they can provide you with the information you will need about the quality of the materials inside the mattress). The more you do ahead of time on the phone the less time you will end up spending driving from store to store and testing mattresses only to find that you like a mattress where the information you need to make an informed choice isn’t even available or the mattresses that you like are outside of your budget range.
I would also check the retail store finders on the websites of the wholesale manufacturers listed on the list because some of them may have some stores that are closer to you that would also be worth considering.
Phoenix