Collecting coins can be considered an investment as well as a hobby. Coins appreciate in two ways; The value of the base metal of the coin (silver-gold-platinum) and the condition, rarity, or collectible value.
You can make money buying and selling coins, but you need to familiarize yourself with the coins you want to collect, coin condition and grading standards, and coin values. Based on the amount of capital you want to invest, you may want to look at popular coins like Morgan Dollars (silver), and American Eagles (silver and gold). Don’t rush, follow values on popular coin sites and eBay, and accumulate coins when you see a good deal. Coins graded (by PCGS or NGC) and sealed in clear cases have value that is verifiable. You also should develop a relationship with a coin shop, their advice could be valuable, and they may be a good source of investment grade coins as well.
This is a good article on Coin grading – Wikipedia.
My answer is straightforward; if you are interested in investment or actively building a coin business, you can make money – as long as you take the time to learn how to value the coins to buy shrewdly or make a profit selling.
Shameless self promotion – I write about coins in my blog, Pocket Change Riches
Thanks for the A2A.