@MarilynG1
I'd like to see the IRS regulations you are using to support use of Comparative Sales Price, please.
From Pub 561 web page, comparative sales is more for property like houses/rare books/etc, where the item you are donating is not an exact match for something sold on the market, so you need to find something "comparable". For stocks/bonds, Pub 561 *clearly* states (see below) that one should take the average of the high/low price on the day of the donation, or from the nearest date if you donated on a day the market was not open.
TurboTax should fill in the form with what the users in this thread have correctly attempted to do (select "average price method"). Whether the stock was inherited or purchased should not impact the sale value or the methodology for determining that value. Maybe it impacts the cost basis determination method(?).
https://www.irs.gov/publications/p561
Stocks and Bonds
The value of stocks and bonds is the FMV of a share or bond on the valuation date. See Date of contribution, earlier, under What Is Fair Market Value (FMV)?
Selling prices on valuation date.
If there is an active public market for the contributed stocks or bonds on a stock exchange, in an over-the-counter market, or elsewhere, the FMV of each share or bond is the average price between the highest and lowest quoted selling prices on the valuation date. For example, if the highest selling price for a share was $11 and the lowest $9, the average price is $10. You get the average price by adding $11 and $9 and dividing the sum by 2.
No sales on valuation date.
If there were no sales on the valuation date, but there were sales within a reasonable period before and after the valuation date, you determine FMV by taking the average price between the highest and lowest sales prices on the nearest date before and on the nearest date after the valuation date. Then you weight these averages in inverse order by the respective number of trading days between the selling dates and the valuation date.
