Ive asked folks with little to no feedback or only feedback from buying baits to ship first. Some agree some dont. If trading with solid members with history and activity thats not only in the black market generally ship at same time without worry
For new members looking to be a contributing member I think shipping first is a good way to show your legit and helps a ton to ease others hesitance to deal with them. I recomend new folks only do that with longtime legit dudes though