In stock market transactions, regardless of whether you buy or sell, you need to pay 0.3% of the transaction amount as a handling fee. A stockholder bought 3,000 shares of a certain stock at 10.2 yuan per share, and then sold them all at 13.5 yuan per share. How much did this investor earn by buying and selling this stock?
在股市交易中，无论买进或卖出均需缴纳交易额的0.3%作为手续费．一位股民以每股10.2元买进某种股票3000股，后又以每股13.5元全部卖出．这位股民买卖这种股票赚了多少元？
<gadget id="calculator">0.3 / 100</gadget>
<output>0.003</output>

<gadget id="calculator">1 - 0.003</gadget>
<output>0.997</output>

<gadget id="calculator">13.68 * 3_000 * 0.997</gadget>
<output>40_916.88</output>

<gadget id="calculator">1 + 0.003</gadget>
<output>1.003</output>

<gadget id="calculator">10.65 * 3_000 * 1.003</gadget>
<output>32_045.85</output>

<gadget id="calculator">40_916.88 - 32_045.85</gadget>
<output>8_871.03</output>

<result>8_871.03</result>