Approximately a billion of these coins have been minted. See a virtually complete collection of Morgan Dollars . There are several key dates and hard to acquire coins in this grouping. There are three of these coins that are particularly difficult to find and quite pricey. The 1893 'S', the 1895 'P' and the 1995 'W'.
Coin collecting is a fascinating and fun past time.
You can collect all kinds of different sets. Silver dollars are one of the most rewarding. Here is a comprehensive Excel spreadsheet that will help you start, arrange and complete such a collection. It is arranged by date, mint and coin type. It includes mint quantities and relative rarity indications in red.