Not particularly, no. They just stand out because the X block isn't printed very often. Until they were recently printed for series 2009 $1 and 2009A $100 notes, the last time they were printed was for series $1 1995 and $100 1996 notes. Y block notes are even less commonly encountered because they were last printed in 1999. It seems apparent that the BEP purposely avoids printing the Y block as well.
I see them often in my cash register at work. I'm not sure if they are more abundant in the Northeast, but I'm in the Boston area, I usually notice they are mostly nice crisp bills, slightly circulated.
Not necessarily. The condition is very important. "In God We Trust" wasn't added to U.S. currency until 1957. Was it a Silver Certificate?
There's nothing special about the X except that it's rare that they get that far in the alphabet before one of the signatories changes and they start all over again with a new series Tables and tables and tables and tables and more than you ever wanted to know is here: http://www.uspapermoney.info
What about a 1957 series $1 bill with an X in the beginning of the serial number? or a red seal $2 bill both beginning and ending with A?
Starting in series 1953, every $2 Legal Tender (red seal) had an “A” suffix and prefix. Nothing unusual about that. Some collectors look for a nice example of high suffixed aces kid the L-X and L-Y block notes.
I live in the midwest in Nebraska and if we find an access always really worn and beaten down. I wish I could find some that were crisp.. I have yet to find a "Y".
The three "X" notes that I know I have are: 1995 New York (B2) 1995 New York (B2) 1988A Atlanta (F6) All three were printed in Washington D.C. I have no "Y" notes yet.