I wanted to use Lux-HQ but I realized that foamdistributing.com only has wholesale price available for Lux-R in the Full Size mattress size. I can get Lux-HQ through FBM, but it is much higher price. I can also get a full sheet of Lux-HQ from FD and cut it but I have no use for the leftover so the price is somewhat wasteful.

At $90 for a 5" thick pre-cut full size Lux-R vs $203 for a full sheet of Lux-HQ, I am wondering if I can get better value with Lux-R? Would I notice a major difference in initial firmness? At what point would the difference in longevity become apparent?

I am considering Lux-R (5") followed by 2" of firm latex followed by 1" of soft latex. I am also considering skipping the 2" of firm latex and getting some kind of convoluted foam. 

Does convoluted foam work well in that arrangement (base/1.5" eggcrate/1" latex)? I am going for a firm mattress.

Thanks for any advice!