If you are collecting Lincoln Cents, it has always been my advice to get the Key Dates first. Owning a key date is often a better investment long term than a variety, high graded common date, or a vast collection of coins. In other words it is better to own a 1909 S VDB in VG worth $800, than a 2001D in MS 69 worth $800, a 1944 D/S in MS 62 worth $800 or a hundred Lincoln's whose value adds up to $800. The 1909 S VDB will always have a greater demand, popularity and resale potential. Of course there are exceptions, but few can argue with the fact that Key Dates have always been great investments. A collection with all the Key Dates missing, will not spark the interest of any dealer. A handful of slabbed 1914 D's on the other hand...