The minimum staking amount is very close to zero. Of course, directly participating in consensus by having the opportunity of building blocks requires 32 ETH (≈$75k), or 16/8 ETH ($37k/$18k) if you run a pool for other people through e.g. the trustless Rocket Pool system.
The minimum cost to acquire an ASIC so that you can even _contribute_ to the consensus is very high (thousands), and to be profitable you have to have close to free electricity. The ironic thing is, that in PoW the "rich get richer" is abstracted away into a combination of economies of scale, and access to free/very cheap power. Plus all the e-waste and wasted power, whereas PoS runs on e-waste people run in their closet, pulling as little as sub-10 watts.
The minimum cost to acquire an ASIC so that you can even _contribute_ to the consensus is very high (thousands), and to be profitable you have to have close to free electricity. The ironic thing is, that in PoW the "rich get richer" is abstracted away into a combination of economies of scale, and access to free/very cheap power. Plus all the e-waste and wasted power, whereas PoS runs on e-waste people run in their closet, pulling as little as sub-10 watts.