What would be enough?

Before adding anything, work out what the machine is missing. It is a smaller gap than it might seem.

The price is easy to state once you know the wine type. Plummy cabernet, 40. Apricotty cabernet, 10. Plummy viognier, 10. Apricotty viognier, 40. Four types, four prices, no complications.

So if something could tell the machine which of the four types this bottle is, the rest would be trivial. The old machine could finish the job in its sleep: four things coming in, one weight each, multiply and add. That is exactly what it is good at.

The trouble is that nothing on the left-hand side reports a wine type. The four units report tastes, and a taste is not a type.

So the missing piece is a thing that answers this:

Is this a plummy cabernet, yes or no?

Something that watches the cabernet unit and the plummy unit, and lights up only when both are lit. Silent otherwise.

Then three more like it, one per wine type.

That is the whole invention. Not a cleverer rule, not a bigger number, not more training. Four new units that each watch a pair.

Where would those four units have to sit?