Over the last three months in the US, the price of DSLR lenses have increased by about 3% while mirrorless has dropped by about 4.3%. The price of used DSLR lenses are still down by more than 7% ...
The short, simple answer is yes; despite their different internal setups, lenses meant for the best DSLR cameras money can buy, or any for that matter, can be used in mirrorless units. However ...