To be honest, I've often wondered about the logic of sales etiquette:

The usual is for the buyer to send the payment and then when it clears the seller (hopefully) sends the item.

But why is it considered more acceptable that way round? It appears that it's OK for the seller not to trust the buyer to send payment, yet the buyer is expected to trust the seller to send the goods.

That just doesn't stand up to logical scrutiny.

I'd suggest that there is a pecking order here. Simply put, the member with the longer standing is the lesser risk (if for no other reason than because a quick search will reveal what they're like to deal with), whereas a newbie is a relatively unknown quantity.

So no, I don't think that you've done wrong at all. Trust has to be earnt: You have and they ain't. End of.