Is your goal to collect each series by date and mintmark or to collect by type? These coins have such a large number of tough issues and outright stoppers that only the wealthiest and luckiest of collectors ever finish a set. Also, are you looking to buy circulated, proof or mint state coins? Again, this is a big decision. You should also be aware of Seated Liberty type fatigue syndrome since it has claimed many a would be collector of these interesting coins. Lastly, you do realize that the Gobrecht dollar is the granddaddy of all Seated Liberty coins, don't you?