There is no connection between the cost to produce a crypto coin and the price, hence your conclusion is a fantasy.

Price is a function of supply and demand only.

If supply of a PoS is fixed or inflates at a predictable rate comparable to a PoW coin inflation rate, there is no reason for the market cap (and price too if total caps are the same) of a PoS coin to be below the market cap (price) of a PoW coin (Bitcoin has a first mover advantage vs all others, PoW and PoS coins, it shouldn't really be compared here for the purity of this experiment as it clearly wins now just based on the adoption numbers).