You would enter the total amount you paid for the stocks sold.  From Turbotax help

Cost Basis

Cost basis refers to the cost or other basis of an investment. In most cases it's simply the total amount you paid for the investment items you sold.

Example: If Connie bought 100 shares of stock at $20 per share, and paid a commission of $15.99 total, her cost basis would be $2,015.99, the total amount she paid. For a mutual fund this amount may be referred to as average cost basis.