In the 1980's mint new issues from British Colonies and Western Europe were marketed extensively as good investments. The theory was that as the number of collectors rose the newer issues would rise in value similarly to the way that the issues of the 1950's had risen by 1980. What the people who bought and sold these new issue investment portfolios didn't realize was that the cause of the rise in price of the earlier material was because insufficient quantities of 1950's and earlier material had been saved and not that demand was so much greater and would continue to increase. The increase in price in 1950's material was not a demand pull increase but rather a supply push as, because of World War II most of Europe and Britain were unable to afford expensive new issues during the 1950's and were catching up in the 1970's and buying those issues then.
The people who invested heavily in the 1970's new issues have done poorly. We just sold at Public Auction an investment portfolio (that had been bought from the new issue guru Jeffrey Needleman) for which the owner paid over $1700 in 1983. It consisted of hundreds of then current British Commonwealth mint sets all still in post office fresh condition. It realized the owner less than $400. A thirty year treasury bond in 1983 was paying over 11% (its hard to remember that interest rates were once so high). If he had bought one of these, our investor would have seen his $1700 worth over $30,000. Bad investment! Ironically, because new issues of the 1980s period were such a terrible investment virtually no one bought any quantities of new issues in the 1990's and 2000's. These have gone up in price.
The people who invested heavily in the 1970's new issues have done poorly. We just sold at Public Auction an investment portfolio (that had been bought from the new issue guru Jeffrey Needleman) for which the owner paid over $1700 in 1983. It consisted of hundreds of then current British Commonwealth mint sets all still in post office fresh condition. It realized the owner less than $400. A thirty year treasury bond in 1983 was paying over 11% (its hard to remember that interest rates were once so high). If he had bought one of these, our investor would have seen his $1700 worth over $30,000. Bad investment! Ironically, because new issues of the 1980s period were such a terrible investment virtually no one bought any quantities of new issues in the 1990's and 2000's. These have gone up in price.