Hi Jared3227,
Post #9 here has more information about trying to “match” another mattress. If you have access to the same types of latex in the same thickness and firmness level and to a very similar cover as the PLB Pamper that you tested then your odds of success would be much higher (assuming that you are confident that the Pamper is a good match for you in terms of PPP) but it’s not likely that anything like this would be available in your budget range so you would need to consider other options that would be different from the “all Talalay latex” design of the Pamper.
A latex hybrid that used a layer of latex over a polyfoam support core would be more in line with your budget but it will be different from the Pamper.
The thread that jankdc linked (thanks jankdc :)) has some good latex or latex hybrid options in lower budget ranges.
I would read post #15 here before considering designing and building your own mattress that is in any way different from what you have specifically tested and confirmed is a good match for you so that you have realistic expectations of success and the cost that may be involved if you need to change any of the layers from your original configuration. The “best” approach to a DIY mattress is a “spirit of adventure” and a willingness to go through some trial and error and where what you learn and the satisfaction that comes from the DIY process itself is more important than any cost savings you may realize (which may or may not turn out to be the case).
Different types of latex can have different properties and a different feel when the layers are put together (see post #6 here for more about the different types of latex) and making changes to a design you have tested can have some surprising or unpredictable results.
The most important part of the “value” of a mattress purchase is how suitable it is for you in terms of PPP because no matter what the cost of a purchase or a DIY design … if it’s not suitable for you to sleep on it would have little value to you.
Phoenix