ANY payment that is for more than the item price, usually claiming to cover shipping or transport (with a story behind it), is a huge RED FLAG.
This is currently a major scam. The buyer convinces the seller to make the payment to a “transport company”, or pays the hauler in person, because the seller believes they’ve already been reimbursed by the buyer. The transporter leaves with the goods.
The payment will bounce, but the seller won’t know it right away. The seller ends up out the goods and the transport money because the transporter/shipper is part of the scam. This is done with live animals including horses and cattle (they cost a lot to transport so they are a great target), furniture, anything in major quantities.
Right now it is very easy for scammers to pass off bad payments of almost any kind other than cash.
The banking system’s payment clearing processes are antiquated, even if they are on zippy software and infrastructure. There are too many steps, firewalls and ponderous communications steps, especially bank-to-bank. Supposedly all that rigamarole protects assets, but actually it doesn’t.