The cost of mining is relatively high. First of all, you have to have a large number of mining machines, which have a high configuration and a large amount of electricity, and the temperature of the mine is also processed. And now it's getting harder and harder to dig, so I don't recommend digging! 
It is right that the cost of mining is very high and due to this many bitcoin miners stopped mining because they cannot fulfill their expenses from the income of bitcoin. When the price is low miners just waste their time and money. They cannot make any profit. It is better to convert your money to some regular business to buy some coins for your future.