Sure but we need numbers, how much more expensive is it, is it 1%, 10% or 100%. Because just saying "more" is compatible with the energy being 0.000001% more expensive. So your comment in not really saying anything.
The practice known as curtailment, is a way for miners to help electricity grids. The miners' steady demand ensures power producers are bringing in revenue to offset costs, but can power off when demand from other sources is high, such as during winter storms.
Show me empirical evidence what you described is actually happening on a large scale.