They're more expensive, to be sure, but they are more effective than the Herbie's products. The VibSensor data plotted in JMP data supports this. And, as we say in science, "the data is data".The 4" high density EVP's necessary to support the (90+ lb.) weight of a Pathos amp between two boards are $200 ea. x four which is roughly 10X the cost of the Herbie's Big Fat Dots. For me that takes it out of the DIY price range. I would opt instead for the superior Wellfloat platform or Delta footers.
Putting them under my REL subwoofer was absolute revelation as they made the entire room signficantly quieter.