In Japan, department stores usually sell "Fukubukuros (Lucky Bags)" every New Year which as the name suggests, is either filled with junk or some excellent goodies but most of the time they'll total to more than what you pay for.
It seems Atlus is offering the same at their online store - 5000 yen (US$53) and 10,000 yen (US$106) bags, with only 100 of each available and offering twice your money's worth in random content. Buyers have 1 in 10 chance of getting a bag featuring limited goods such as a figure of Rise Kujikawa (Swimsuit, D Shop Limited Edition) from Persona 4.
Hmmm, bit pricey for me to gamble to be honest... I would rather use that money on the Persona silver pendant if it was still available. But the surprise part was fun when I tried some other lucky bag.