So taking everything into account the summary is this:
Sancho probably would prefer to come to United to be back in England and play a major role in bringing our club back to the top. However, he is also really happy where he is right now and has no pressure with age being on his side, and things look bright for Dortmund with some great young players. So he won't force a move.
Dortmund have no economical need to sell him. And despite the actual crisis things will be more or less back to normal in one year, and his market value might be even higher then. So this is similar to the stock market, where prices are low right now. However, you won't sell at this moment as this would be a stupid thing, given that sooner or later the prices will reach higher levels again. The big clubs will come back and invest heavily in 2021/2022 so no sense in giving assets away for cheap.
Woodward seems to be sure that something like 80 Mio should be enough right now, as the economy lies on the floor. I could see Dortmund accommodating us with a small discount or some kind of structured deal, but surely not a 25% discount.