Hi skygraff,
The first place I would start is post #1 here which will give you some of the basic information and guidelines that are most helpful when you are looking for a mattress. This and the posts it links to are the “basics” you will need that will answer many of your more general questions and perhaps most importantly give you a step by step process for choosing a mattress.
Once you have some basic information the next step would be some local testing on mattresses that have similar designs and materials (that the manufacturer or retailer discloses) to the ones you are considering so you have a reference point in terms of how a mattress you are considering may feel and perform. Online manufacturers, particularly of memory foam, may be able to suggest local mattresses that are more widely available such as one of the Tempurpedic line that have a similar “feel”, quality of materials, or design (or all three in a few cases). No matter what the quality and value of a mattress (which you can only tell by knowing the specifics and quality of all the layers) … if a mattress isn’t suitable for you then no matter what the quality and value it would have little value to you. Words like “plush” and “firm” are mostly subjective and relative to each person and have little meaning without a specific reference point.
The risk of an online purchase can be lowered by having similar mattresses that you can compare in local testing (that have been “tested” to be comparable in real life and not just for the sake of marketing and selling a mattress), the knowledge and experience of the people you are dealing with and the quality of any advice and guidance they provide, or with an exchange or return policy that can be your “fallback” if you make a mistake in your comfort choice and need to fine tune or make changes to the mattress or send it back because it’s not suitable for you. These are all an important part of an online purchase. I would also make sure that you talk on the phone to any online manufacturer you are considering because the types of conversations you may need to have where “it depends” can be part of the answer to most seemingly simple questions are much more effective with voice communication. I would only use email or chat for very simple questions that have simple one line answers. Questions like “which mattress is best for me” which need much more background information to answer in any meaningful way than just basic height and weight information should never use written communications IMO.
To make meaningful quality and value comparisons between mattresses you need to know the thickness, type, and quality of all the layers and components. All good manufacturers or retailers will provide this to you so you can make more “apples to apples” comparisons as much as possible. I don’t see the specifics of the layers on the Plushbeds site and you would need this to make meaningful comparisons to any other mattresses.
For example … the Plushbeds Grand Royale uses 8 lb memory foam, 5.3 lb memory foam, and a high quality polyfoam base layer and sells for $2999 while the Select Foam Regalis uses the same materials and sells for $1599 (both in queen). In order to make a meaningful comparison between them though … you would need to know the thickness of all the layers because if one mattress has twice the amount of high quality foam it may justify the higher cost.
Other parts of your personal value equation that may be an important part of any comparison for you would include any other add-ons that each includes, your confidence that either of them will match your specific needs and preferences, and any differences between the return policies between them. All of these and all the other objective, subjective, and intangible differences that are important to you may all be part of your personal value equation. The best time to make comparisons between them is when you’ve narrowed down your choices at each manufacturer to one.
Some other posts that may be helpful that aren’t linked in the “read first” post include …
Post #13 here about reviews. Reading reviews is very different from actual mattress research and for the most part not very relevant as far as choosing a specific mattress because a mattress that is “perfect” for one person may be completely unsuitable for the next.
Post #9 here about Tempflow
Post #12 here which includes some of the better online memory foam choices I’m aware of (also listed in the “read first” post I linked).
This thread may be useful for ideas on disposing of a mattress (and this site has a couple of options listed for Chicago).
Phoenix