We found these at the LEGO store on Michigan Ave. for $2.99, but they are not available online. After calling the store today, the woman told us that after releasing the 1.5" tall black & white set, they "sold like hotcakes." At the start of January this year, the Chicago store received a couple cases and now they are long gone, and they don't know if or when they will get more.
Online we only spotted this goofy set for $4.99, which we don't like nearly as much. Seems worth investigating where else you might find the b&w ones ($2.99!) if you love them as much as we did.