lucky bag; mystery bag; grab bag
A sealed bag sold at a set price, especially during New Year sales, containing a random assortment of goods whose total value is usually higher than the purchase price.
Buying a lucky bag at the department store on New Year's Day is an annual pleasure.
You won't know what's inside this mystery bag until you open it.
I bought a lucky bag at the department store on New Year's Day.
There were many people lining up for lucky bags from early morning.
You don't know what's inside a lucky bag until you open it.
This shop sells lucky bags every year at its New Year's first sale.