Hi Dishdok,
Welcome to the Mattress Forum! 
I switched your post to a new topic of it’s own so your questions wouldn’t get mixed in with another member’s topic.
The best place to start your research is the mattress shopping tutorial here which has all the basic information, steps, and guidelines that can help you make the best possible choice … and know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort” and PPP (Posture and alignment, Pressure relief, and Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists (based on all the parts of your personal value equation that are most important to you).
The first “rule” of mattress shopping is to remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort” or PPP (Posture and alignment, Pressure relief, and your Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
Lucid 12"
While I can’t speak to how a mattress will feel for someone else or how two mattresses will compare in terms of comfort and PPP … outside of PPP the most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t “feel” and assessing the durability and useful life of a mattress depends on knowing all the specifics of its design and construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label (or how a mattress feels in a showroom or when it is relatively new) so I would always make sure that you find out the information listed here so you can compare the materials and components to the quality/durability guidelines here to confirm that there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
You can see some comments about Lucid and other Chinese mattresses that are shipped compressed from overseas in post #6 here. I would also avoid any mattress that used 2" of 3 lb memory foam in the comfort layers of the mattress. A forum search on Lucid (you can just click the link) will also bring up more comments and feedback about them as well. This certainly isn’t a mattress that I would consider.
Gel Memory Foam 10"" by Exceptional Sheets
The 3" of 3 lb gel memory foam in this mattress is also a lower quality and less durable material that I would consider to be a weak link and I would avoid this mattress as well.
If you are considering an online mattress then the tutorial includes several links to lists of some of the better online options I’m aware of (in the optional online step).
There is also more information about choosing an adjustable bed in post #3 here and the main adjustable bed topic that it links to that can help you choose an adjustable bed based on price vs features comparisons and also includes some retailers that you can use as good sources of information about the features of the adjustable beds they carry and as pricing references as well (in post #6 in the main adjustable bed topic). Of course there are many other sources as well and prices can change on a regular basis so I would also include some internet searching in your research and I would also keep in mind that online advertised prices are often price controlled so make sure you call the stores you are considering to find out their best prices rather than just looking at the prices that are listed on websites.
Phoenix