Possible Questions:
- Collector's item
- One for the books
- Curio
- Uncommon thing
- Blue moon, e.g.
- Uncommon occurrence
- It doesn't happen often
- Hole in one, e.g.
- Unusual occurrence
- Unusual find
- Uncommon item
- Thinness
- Something unusual
- Snow in Tampa, e.g.
- Oddment
- It occurs once in a blue moon
- Hen's tooth, e.g.
- Hard-to-find album
- Collectible, maybe
- Albino, for one
- Snow in Miami
- Seldom-seen thing
- One-in-a-million thing
- It hardly ever happens
- Hole-in-one, e.g.
- Good used car, e.g.
- Factor for a collector
- Diamond value factor
- Blue moon, for instance
- Appraiser's concern
- 78 speed records, e.g.