Hi RafB,
I deleted the other post 
There are many smaller manufacturers in most areas of the country who make mattresses that use higher quality materials than the major brands … better construction methods … and best of all sell for significantly less than anything comparable that you will find with more heavily advertised major brands or chain stores. Many of these sell direct to the consumer and some wholesale their mattresses to local outlets who then sell them to consumers. They operate at a smaller profit margin and have a smaller supply chain and less “mouths to feed” between the manufacturer and the customer which is a big part of the reason they are such great value.
These manufacturers can be rather hard to find as they are often smaller and don’t advertise at all and rely much more on word of mouth and their own local reputation. In many cases they have been in business for decades or even three or four generations but as strange as it may seem … most of the local population has often not heard of them and tends to “follow the advertising”. They can be found of course with time searching on the web although even then some of them only show up deep into a search. A big part of the reason for this site is to help people find them.
The difference between these and many foam shops (which can also be great) is that they have a showroom where you can actually try out their mattress rather than having to design it yourself (which can take a lot of knowledge that many people don’t have). They are also very good at making adjustments in their “standard” models if necessary to fit a mattress to your needs and preferences.
They are also very good at choosing materials and using construction methods that they know will last because their reputation depends on it. Buying from a good local manufacturer can save a lot of research as well because as a general rule … they are far more interested in making sure you are happy for the long term than they are in making the sale.
With the size difference between you and your wife … it can be particularly important for the person who sells you a mattress to really understand the benefits of different materials and constructions and even make a mattress which has “split” layering if necessary to accommodate different weights, body shapes, and sleeping positions.
You are wise to avoid mattresses like the MySide series 6 as they are considerable overpriced IMO based on the materials that are in them. Some guidelines which can help people avoid most of the lower value choices can be found here.
There are some good options in the Boston Area and other helpful information in this thread which hopefully can help steer you in the direction of better quality and value.
Phoenix