Hi EddieC,
Restopedic does make a range of innerspring mattresses yes but I’m not familiar with the specifics of the materials in the mattresses they have on their floor and it’s always best to talk to them directly for this type of information. They can also custom build. There is some generic information about each of their mattresses on their site here but it’s always important to make sure you know the specifics (see this article).
Having said that … smaller local manufacturers such as Restopedic would typically use higher quality materials in their mattresses in every budget range than the larger mainstream manufacturers.
The mattress shopping tutorial has more information about finding a mattress that would “stand out” for you (a mattress that is best for each person would be unique to that person). In most cases … the “materials value” of the mattresses made by the same manufacturers would be similar across their lineup although mattresses in higher budget ranges will usually have higher margins. There is also more in post #13 here about the most important parts of the “value” of a mattress purchase.
Phoenix