Hans is Stendker distributor so I guess he sells Stendkers good heart mix.The price for Stendkers good heart is the same here in Europe too and it's a darn good mix, well worthed the money IME.
I don't do beef heart mix , I just hand grate it straight from a freezer . Maybe that would be a more convenient option for you too .
It can last more than a year in a freezer.