Paid-in capital from treasury stock is the amount of difference between the cost and the sale price of the treasury stock.
In the given problem the treasury shares were purchased for $2 per share and 500 shares are sold for $3 per share. Hence Paid-in capital from treasury stock shall be 3-2 = $1 per share and Total Paid-in capital from treasury stock shall be 500 shares * $ = $500
Hence the answer is $500