Did We Run Out Of Cows??

We can buy a mix here that is 80/20 fat and a beef pork mix. I suspect the pork makes up most of the fat content. It's call Boston (?) burger and is on sale often for $2.69, regularly $2.99. It makes the best grilled hamburgers.
It has only been around here 2 or 3 years and has been very popular, but other grocers have copied with poor results and we found we have to buy it from one source.