I want to change price depending on checkboxes ticked. How to remove if statement from onSubmit()

I want the users to select items form checkbox and submit a numerical price according to the items selected. I have tried it here using if statement. How to do this efficiently?? i had tried to map the states using this.state.map() but its not working also.

  constructor(props) {
    super();
    this.state = {
      check1: false,
      check2: false,
      check3: false,
      check4: false,
    };
    this.onCheckChange = this.onCheckChange.bind(this);
    this.onSubmit = this.onSubmit.bind(this);
  }

  onCheckChange(e) {
    this.setState({
      [e.target.name]: e.target.checked,
    });
  }

//**************i want to change this ****************

  onSubmit(e) {
    e.preventDefault();
    var price = 0;
    if (this.state.check1 === true) {
      price = price + 10;
    }
    if (this.state.check2 === true) {
      price = price + 20;
    }
    if (this.state.check3 === true) {
      price = price + 30;
    }
    if (this.state.check4 === true) {
      price = price + 40;
    }
    console.log(price);
  }

  render() {
    return (
      <div>
        <Form onSubmit={onSubmit}>
          checkboxes are placed
        </form>
      </div>
    );
  }
}

export default SellComponent;