Any modern issues catch your eye as a possible unnoticed rarity? I think that the unc $5 gold commems qualify. Cladking may have some worthwhile thoughts on this one.
A few......1982 and 1983 UNC coins.....also maybe things like the 1970-D Half. I don't know and I'm only guessing since I don't collect moderns.....but I think the ones I've listed are what I've seen CladKing list in the past...I'm sure there are many more! Speedy
Unnoticed - no. There are plenty of moderns out there that command significant prices. But most of them are conditional rarities - it depends on the grade and sometimes on a special designation like FS or FBL. But they were noticed long ago, otherwise they wouldn't command such prices.
I seem to remember that a 1986 Comm Half was found with a rotated rev of 180o.....I would also say that it is a rarity unnoted by many. Speedy
I think the $2.50 gold liberty coins probably qualify as an unnoticed rarity. Some of the mintages are tiny, the surviving populations are probably even lower, and the Redbook prices are fairly modest.
How about rolls of 2005 and 2006 unc dimes and cents. Not the satin ones. The fact that you can not get them from the mint at all means that they may be something. No nonsatin unc cents or dimes in mint set or mint rolls!!!
But you could get them from mint sets (but not anymore) that spells opportunity to me. Most collectors get their current year coins from mint sets.