It is common to encounter units which make meaning even when the reciprocal is taken. For example while ohm is the unit of resistance the reciprocal denotes the conductance and is called not surprisingly mho!
Travelling on a short stay to UK I was ready to see lbs instead of the Kg at least in the local market. It however a surprise to see that almost of them have moved to Kg. So I noticed for example it said Granny Smith Apples at 1 Kg for one £. One kg per pound, yes that was clear. So were two large aubergines per pound.
Then I came across a price tag which said 2 pound/kg. I thought I read it wrong. But no! The local ironmonger was selling metal artifacts and was pricing them at 2 pounds per Kg! That too was ok. Then I found someone selling pounds by the kilo and they turned out to be dog pound being sold by weight. So all goes here, Kg/£, £/Kg, pound/£, and £/lbs (rare).