I live in a fairly HCOL area in a state with some of the highest gas taxes (California). Gas is $4.19/gal* and ground beef is $6/pound. So my guess is that they're in the Bay Area OR just shopping at very expensive places

*Here in Los Angeles there's a handful of gas stations that inexplicably charge $1-$2 more than any other one. I always assume it's either money laundering or they just prey on people who aren't paying attention. $4.19 is just the cheapest price I've driven by in the last 24 hours