I was searching far and low in DC and MC. After calling every grocery store and hardware store I could think of, I finally bought it from Amazon, where it was available for SAME DAY DELIVERY for something like $6, for $12 worth of product (4 boxes). It arrived a couple hours later. Amazing, right?

Hardware stores are usually good for canning stuff (though don't know about liquid pectin specifically), also surprisingly, Target.

I'm pretty sure I got my last bottle at strosneiders.... They have a big canning section.

Anyone know what store would have it? Thanks