Today, coin collecting has become a hobby, not only for kings, but for the ordinary people as well. Now, everyone can be a collector of currencies because much has changed in how coins are made and how they are used. Today, coins are made from cheap metals like aluminum, brass, nickel, and stainless steel for those in normal circulation. The metals used are not very valuable themselves. You cant melt our coins today to make higher value coins. These have a numerical value equivalent or what is called face value and has nothing to do with the value of the metal used to make them. The introduction of paper money was also a game changer in collecting coins and currencies because paper, compared to gold and other metals, is relatively cheap to produce. When currencies get demonetized, they would lose their value and just become useless pieces of metals and paper. Unlike if we still used gold for coins, our money would never get demonetized because gold in itself, coin or not, is very valuable.
If you want to start you own coin collection, start with what you have in your pocket. Check your old piggy banks and forgotten nooks and crannies of your grandparents' house. More often than not you will find old collectibles in these places. Ask friends and family members for old demonetized currencies they don't want anymore. Go to coin trader shops and rummage through their bargain bins. Ask experts and do some research. You can specify your collection to only local coins, or coins of a specific year or a specific series.
Despite coin collecting becoming an ordinary mans hobby, it has become more complex. Collecting now goes beyond just keeping the coins, it means maintaining the coins condition and appeal, protecting them from the environment, and having to spend a small fortune in albums and display cases for your coins. The coins may have been demonetized, but their collectors value will become higher just because the bank doesn't make them anymore. Prices for out of production coins, especially the old ones, depend more on how much you are willing to pay to have one in your collection rather than how valuable the metal content is. I remember buying a Pilipino series 1 peso coin (1972), for 50 pesos. That's 50 times its face value just because they don't make them anymore. It would have bee much more expensive of the coin was in mint condition. Coin collecting is a great hobby, you cant beat the satisfaction you get when you find that elusive coin you've always wanted.
It may have been a hobby of the kings in the past, but today, anyone can be a king of this hobby.