[originaltext] The price of Chinese zodiac stamps commemorating the 1980 Yea

The price of Chinese zodiac stamps commemorating the 1980 Year of the Monkey have rocketed to a historical high for a number of reasons, according to National Business Daily.
    As the first of its kind, these monkey stamps are sought-after items, with a single stamp fetching 12,000 yuan, much more than its original face value of 0.8 yuan. The complete set of stamps is priced at 1.5 million yuan.
    The reason for its high valuation is based on the fact that it was the first time China Post released stamps featuring the Chinese Zodiac since the establishment of the People’s Republic of China in 1949.
    Since then, China has been issuing stamps on the theme of the lunar Calendar every year to mark the 12 Chinese astrological signs.
    Small circulation also contributed to the monkey stamp’s record price. Only five million "Golden Monkey" stamps were released for circulation in 1980, and they are exceedingly rare now.
    In addition, the 1980 stamps were designed by Huang Yongyu, 92, a well-known Chinese master painter, making it a collectible item with extreme value.
Questions 5 and 7 are based on the news report you have just heard.
5. What is the passage mainly about?
6. How much does the complete set of stamps cost?
7. Why has the price of monkey stamps from 1980 rocketed to a historical high?