Tax = Purchase Cost × Minimum Wage(Moment of Purchase) ÷ Minimum Wage(Moment Tax is Charged)
You can multiply that all by a magnitude term, depending on the taxation frequency, or to charge more/less.
This is a totally arbitrary formula intended to discourage holding non-cash assets that provide no intrinsic utility, and it incentivises owners to raise the minimum wage.
It isn't hard to come up with these sorts of measures, in fact I bet you the reader have some ideas about how my suggestion can be improved. A team of experts could come up with something much better, and they CAN be enforced (don't believe their lies). You just need to disentangle yourself from notions of rules-based "fairness" that exist to justify & preserve our presently lawless economy, where might makes right.