The DM lands on a Wednesday night, usually after ten. A photo of a four-node Philodendron spiritus-sancti cutting, slightly out of focus, one aerial root reaching. Below it: "Open to trades?" You stare at your own shelves — the variegated Monstera that throws half-moons more often than it should, the Anthurium warocqueanum you grew from a sad import, the Hoya carnosa 'Compacta' that nobody actually wants but everyone owns. You start doing math that has nothing to do with money.
Trading is the older economy. Before the Etsy listings and the auction groups and the cold gloss of PayPal Goods and Services, collectors swapped cuttings across kitchen tables and shipped them in damp paper towels with handwritten notes. The practice survived the boom because it does something a sale can't: it makes two growers into something closer to colleagues. But it also goes wrong constantly, and the reason it goes wrong is almost never greed. It's that nobody talks about how to actually propose one.