card.js

import React, { Component } from 'react'

class Card extends Component {
  constructor(props) {
      super(props)
      this.state = {price: ''}

      this.handleChange = this.handleChange.bind(this)
  }
  handleChange(event) {
    this.setState({ price: event.target.value})
  }
  render() {
    const lesson = this.props.lesson
    if(lesson.description === undefined) {
      return <div></div>
    }
    return (
      <div className="card row col-md-12">
        <img src={lesson.imageurl} className="col-md-3" />
        <div className="col-md-6">
          <div className="card-title">{lesson.productname}</div>
          <p>{lesson.description.short}</p>
       </div>
        <div className="pull-right col-md-3">
           <div className="input-group">
              <input type="text" name="discount_price" value={this.state.price} className="form-control" onChange={this.handleChange} />
            </div>
            <s><strong>{lesson.price._} {lesson.price.$.currency}</strong></s>
        </div>
      </div>
    )
  }
}

export default Card