So, perhaps the old mantra that there was only gift exchange going on is incorrect.

See:
https://phys.org/news/2019-08-northw...ronze-age.html

"People in England were using balance weights and scales to measure the value of materials as early as the late second and early first millennia BC. This is what Professor Lorenz Rahmstorf, scientist at the University of Göttingen and project manager of the ERC "Weight and Value" project, has discovered. He compared Middle and Late Bronze Age gold objects from the British Isles and Northern France and found that they were based on the same unit of weight. This confirmed the hypothesis of the research team of the project that there was already expertise in using standard weights and measures in many regions of Europe at that time. The results were published in the journal Antiquity."