I thought there were some hints of barter of sorts in palace economies from shipwrecks - no currency but incoming exotic commodities they couldn't produce and o

I thought there were some hints of barter of sorts in palace economies from shipwrecks - no currency but incoming exotic commodities they couldn't produce and outgoing ships of commodities well beyond any personal use implies some trade relationships. The fact Palace Economies all died out doesn't mean a barter economy never existed, just that it wasn't stable enough to leave any isolated "time capsule cultures". Granted palace economy commerce isn't on a personal level unless you count the ruler who allocates everything.