why does turbotax 2025 insist on inserting "comparative sales" instead of my selection in the interview of "average sales price"?

Forms mode enters the wrong information.. The interview asks, and the "info" button says"

What valuation method applies to stock?

The valuation method is whatever is used to determine fair market value. For stocks, that usually the average share price. This is the average of the stock's highest and lowest selling prices on the date you transferred it to the charity.