I'm not sure if people buy them directly in treechat. treechat users tend to be more focused on different discussion topics and creating but as for an on-app market I dont think thats one of treechats focus as zoide and 3dordi have a lot of features and functionality. if you click on an ordinal you own, at the bottom if gives you options to view the ordinal on 1sat, zoide or 3dordi
both @66034 and @146002 (creator of 3dordi) are on here and treechat if you want to delve further into them, or ask users on treechat theyre very helpful.