I was thinking of the similarity of this concept with the Indus and Harappan scripts.
If you look at their seals of which thousands have been found you'll see this up arrow being a vertical fish shape. So it's a multiplier.There are seals with 2 vertical fish between two other shapes which could be numbers. This is the same as the power tower concept! Has to be.
On some seals there is a vertical fish with an inverted v above it. This could be just be a replacement of the 2 up arrows.
So a horizontal line of the Harappan scripts on seals is just that. So many units of a product. Followed by its total price. Like an invoice.
The odd shaped further would be its destination. And person to hand over.
The other seals could be the money received as payment. This would-be indicated by the animal type beneath it.