Hi LauraC,
You can read a bit more about the Prana mattresses in post #3 here. As you can see they all have thick layers of polyfoam over the latex so you are sleeping more on polyfoam than latex and they don’t have good value compared to many other mattresses that use similar amounts and quality of latex. There are many similar options available at much more reasonable prices.
Just in case you haven’t read it … post #1 here is always the best place to start when you are looking for a new mattress.
Some of the better options and possibilities in the Washington, DC area are listed in post #2 here. No matter who you are dealing with though … always make sure you can find out all the details of every layer in a mattress you are considering. This is the only way to assess the quality, value, and durability or the potential weak links of any mattress.
If you are comfortable going in an online direction then some of the members here that sell latex mattresses online and have among the best quality/value in the country are listed in post #21 here.
In terms of materials … yes … and at much better not just a bit better prices. You would need to asses how close they were in terms of feel and performance though. You may want to consider trying some of the Pure Latex Bliss mattresses (or any other talalay latex mattresses which is what is used in the Prana) to see how they compared in terms of feel and performance for you.
One step at a time following the guidelines in the “guidelines post” I linked earlier will give you the best possible odds finding your best mattress and most of all finding the “experts” that have the knowledge, experience, and integrity to help you make great choices.
Phoenix