Current stock of RX Vega 64 are £950 and restricted to 1 per customer, so not aimed at miners. Obviously mining is creating the shortage that pushes prices up generally but you can't say that people who bought cards for nearly a grand before there was any shortage didn't add fuel to the fire.
When there is a limited stock of particular TV, do John Lewis increase the price of their limited stock by say 40%? No, whats so special about pc components that pc retailers find this acceptable behaviour?