When buying Federal Reserve notes....

the more recent a note is, the less it will be worth obviously.  You should obtain the highest quality note you can find.  The older it is the more it will be worth.  You might think about obtaining a lower grade note and working your way up.  When you buy a better looking example, sell your other one.  This way you can work your way up to grand collection.  Remember it is not a race.  You can't be impatient when in this community.   

It will take a while but it will mean more to you in the end.