Mmm. You wanted to use Konjunktiv there, but used second person singular instead of third person (which &quot;man&quot; is), but more importantly, this is a bit of a special case. Whenever either Konjunktiv I or Konjunktiv II has a form that is similar to another one (like a past tense form), then people usually use the other Konjunktiv to supplement it with, mostly to eliminate ambiguity. It is true that Konjunktiv II would apply here, your thinking was correct, but &quot;Kaufe man [...]&quot; would be better. 