Although crypto-currency mining is undoubtably a thing, I think the bigger issue is that the countries where there are big markets for these components currently in lockdown so instead of spending cash on holidays, days out, airshows (cough) etc people are building/upgrading PCs and so stocks get tighter as a result. Scalpers also are a problem and there is evidence that some companies are supporting this trend (MSI were called out on it recently).
The shortage of memory in the wild has lessened over recent months as factories in the Far East have come back on stream. Certainly I had no issues purchasing a 32GB kit a month ago.
Each to their own Kev, but I think 2K is too much to spend on a graphics card when soon you'll be able to spend half that and get an overclocked 3080 and have change. I'm not sure that the extra cost for the 3090 is borne out by the performance gains. What is happening for definite is that manufacturers and suppliers are hiking the prices of the cards they have which does sound rather like profiteering to me.
Fortunately. in my case my antique 980 will give me 100+ FPS in GBS at 1080p with all the bells and whistles on so although an upgrade would certainly be nice, in the current insanity it's not really a necessary (or viable) course of action. In the meantime I have a big servicing bill coming up for the car and it'll need new boots before the summer so...