Not sure what you mean, is there a typo here? What seller wouldn't want someone to pay them using F&F where there is absolutely no effective resource should there be an issue? Did you mean to say avoid the buyer who won't pay using F&F? Or maybe avoid the seller who insists on F&F? The latter is definitely true, even for F2F transactions.The biggest red flag is not wanting to pay using family and friends. Run from any seller that won't allow payment this way!