Hi Thatg,
The first place I would start your research is the tutorial post here which has all the basic information, steps,and guidelines you will need to make the best possible choices … and know how and why to avoid the worst ones.
I would keep in mind that every manufacturer or retailer may have a different idea of what “medium firm” means. There is no specific definition or consistency with comfort ratings and they can vary widely between different manufacturers. In addition to this different people can have very different perceptions of the same mattress depending on their body type, sleeping positions, and individual preferences and sensitivities. What feels too firm for one can feel too soft for the next.
When you are dealing with an online supplier then the most important part of the purchase is their knowledge, experience, and willingness and ability to help you decide which of their mattresses have the best chance of success for you based on a more detailed phone call (not email) that includes the information you provide them about your body type and sleeping positions, your local testing and the mattresses you have slept on in the past, and any other information that can help them help you make the best possible choices.
No matter what the cost of a mattress … if it’s not a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) then it would have little value for you if you can’t sleep on it.
I would also make sure you only deal with manufacturers or retailers who are completely transparent about the quality of the materials inside their mattress (see this article). If you buy a mattress that uses low quality materials then no matter how it feels and performs … if the materials soften or break down in a matter of months and you lose the comfort and support that is suitable for you and you need to replace it then the mattress would also have little “value” to you (unless it’s just for temporary use).
The tutorial post also includes a link to some of the better online memory foam choices that I’m aware of.
I would be very cautious with this and if you have no recourse if the mattress isn’t suitable for you then I would be very hesitant unless there was a return policy that didn’t cost you almost as much or more than the mattress for return shipping or any return costs. If there is no warranty then the odds are high that you would be buying a used mattress, a comfort exchange, or a warranty exchange. All of these would be buyer beware IMO.
“Cheap” mattresses where you have no idea what you are really buying can be very costly in terms of the quality of your sleep, how often you may need to replace them, and the costs involved in returning them if they aren’t suitable for you to sleep on. Price is only one of the parts of the “value” of a mattress and consumers who shop based only on price are generally the easiest to take advantage of and sell a “junk” mattress to (that is worth less than they paid for it) because they often don’t look at anything else or make meaningful comparisons with other mattresses or retailers based on all the parts of their personal value equation that may be important (and it’s important to use foresight rather than hindsight to decide what may be important to you). There can be a very big difference between “value” and price.
Who you deal with and their knowledge, experience, and integrity can be one of the most important parts of a successful mattress purchase.
Phoenix