I don't think you understand how bitcoin works. The cost to mine bitcoin will always be however much it's price is (minus some profit), be that $1000 or $10000.
At $1000 what would happen is that people will drop out, difficulty will drop and suddenly each bitcoin costs $1000 to mine.
If the price is $10000 then more people will pile in, difficulty will increase and suddenly it costs $10000 to mine.
Obviously this mechanism doesn't react to sharp swings, but if the entire basis of the value of bitcoin is how hard is it to mine, then the price can be as low as you want or as high as you want. It provides no lower bound or upper bound.
With the sharp drop in price recently this has already started happening.
https://www.blockchain.com/en/charts/difficulty
Also remember better ASICs actually make it cheaper to mine if difficulty didn't change to correct that. Hence the gradual upwards march.