Why spend more than $25 per piece of equipment on vibration reduction?

yes - magnetic levitation, air suspension

Still points are superior but at over $100 each expensive ,

better  then hockey pucks ,or vibrapods ,is from Herbies tube dampers 

his tall tenderfeet ,they are made of a special isomer from  Germany I have used these for years, very  good  for $16 don’t break the bank.

Vibrapods #1 to #5 along with their cones seems fine to me. I put the higher number vibrapod under the heaviest section of equipment, typically the transformer. Also use those rubber/cork sandwich squares which seem to work well. Lastly, I use numerous Butcher Block Acoustics supports, some with cones, some with adjustable rubber feet. They are economical supports and look nice as well.

The Vibrapod website has some nice tips and tutorials on how to use them properly, including how to utilize them in a vibrapod sandwich. I just don't see the need to spend much more on these things, I'm also on a concrete slab. Turntable resting on dedicated shelf  mounted to a concrete wall. No issues there.

I had some hemisphere shaped black rubber. Not sure if they wre brand name. They were on my subs for some time. When I heard about the springs, i replaced the rubber ones. Immediately, the bass was detailed, deeper, enveloping. I believe the rubber is for absorptiondamping, springs are isolating. I have a concrete floor. Also, the music used to be much boomier upstairs.

The only device that needs isolation is the turntable. The best come so equipped like SME, Sota, Dohmann, Avid and others. Everything else could care less. It is just audiophile mythology.