Hi TDI Hoo,
Paramount is a privately owned manufacturer that in general terms I would consider to be one of the 'better" quality/value choices. Retailers that carry them have also told me that they are transparent about the materials they use. I don’t know the specifics of either mattress you are mentioning but you should (hopefully) have little difficulty finding out the details of the layers and components so you can make meaningful comparisons. As you mention … google searching brings up no meaningful information about them and their site only has more generic information that doesn’t mention any specifics about any of their mattresses.
Original Mattress also uses good quality materials for their budget range and you can see some examples of the foam densities they use in post #32 here although they can vary with each mattress. While every salesperson there is unlikely to know the specs off by heart … they all have a book where they can look up the specs of all the layers in their mattresses. On some occasions you may find a salesperson who seems reluctant to do this but the information is available to all of them. The Classic series is a basic Bonnell coil mattress with cotton and polyfoam comfort layers and is the softest of the two sided models in the line. If the majority of the polyfoam is 1.5 lb density then it would be reasonable to expect some foam softening and impressions over the course of 5 years but nothing that would affect the quality of sleep over the course of 5 years or longer if the mattress is suitable for her body type, sleeping style, and preferences. I would also make sure you purchased it as a set because the boxspring can be an important part of both the performance and durability of an innerspring mattress.
If any of the retailers you are dealing with provide you with the specs but aren’t able to explain what they mean then of course you are always welcome to post it here and I’d be happy to make some comments about a particular mattress you are looking at.
In case you haven’t seen it (although I suspect you have from your research and previous mattress purchase from Cozy Pure) … some of the better options in the Richmond area are in post #5 here. I know from previous conversations with her that Michelle from Bedcrafters is particularly knowledgeable about mattresses and materials and would probably be well worth a phone call or a visit as well. Some of the Golden mattresses at Richmond Bedding are also good quality/value and they have double sided mattresses there with higher quality foams as well.
Phoenix