2009 Unc Set?!?

*** Moved by Staff to a more appropriate forum. ***

I was wondering if someone can clue me in;

I was considering buying several "born in" uncirculated sets based on the year my nieces and nephews were born in;
One of my nieces was born in 2009;
Looking at the published mintages, the 2009 'born in'/baby uncirculated set appears to be valued abnormally high - yet it has the same mintage as the following year's same set.
Book value has it at $100 ( ebay prices are double or triple that), while '04-'06, '08, & '10 are all $20-30, but '07 & '09 are way high.

AFAIK there is nothing unique to this set other than the quarter (obviously) - so I cannot see why the value is pegged so high.

Can someone please enlighten me?

Thanks!