I'd like to address the topic of when a collection is "complete."
For my own purpose(s), a set is "complete" when it contains an example of every date and mint which entered circulation as a working coin.
Proofs do not count, by this criterion.
Nor do "errors."
Nor do experimental pieces.
I'll use a Greysheet to help.
1)
Indian Head cents.
Do you really need to include the 1856, 58/57 and 69/69 to call your collection complete? I say no.
2) Lincoln Cents of the Wheat design.
Retract your claws, folks, I consider this to be classic!
The 1922 "plain"*, 44D/S and the 1955/1955, while dandy variations which have caught the eye of collectors, are not needed to make your set complete.
*I have never forgiven Dansco for including a hole for this
"variety" and nothing more.
3)
Liberty nickels.
35 regular issues. 35 examples make the set complete.
RELIEF!
Although I added a gold plated 1883 "no cents" as an historic curiosity.
4)
Buffalo nickels.
Tough enough without chasing down examples of the 16/16 and 18/17D. 1937-D 3-legged? Give me a break! Not needed.
5)
Barber dimes.
My set is complete but not finished.
It will NEVER be finished.
The 1894-S is NOT NEEDED!
6)
Mercury dimes.
I say skip the 42/41 and 42/41D. Nice, but not needed.
7)
Barber quarters.
Again, no varieties to deal with.
8)
Standing Liberty quarters.
1918/1917S? I'd take a 1916 any day!
9) 10) and 11) The Halves.
Barber, Walking Liberty and Franklin.
Easy. No major varieties to deal with.
My point is this:
Only YOU can define what constitutes a complete set.
My opinions are mine.
My goals are mine.
The whole point of collecting by series is to satisfy YOUR goal, and no one else.
GOOD HUNTING!